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„  -  4  UNIVERSITY  gf CALIFORNIA 

\  COLLEGE  of  MINING 


DEPARTMENTAL 
LIBRARY 


BEQUEST  OF 
SAMUELBENEDICrCHRlSTY 


PROFESSOR  OF 

MINING  AND   METALLURGY 

1885-1914 


A     MANUAL 


BLOWPIPE-ANALYSIS, 


AND 


DETERMINATIVE  MINERALOGY. 


WILLIAM    ELDERHORST,   M.D., 

PROFESSOR    OF    CHEMISTRY   IN    THE    RENSSELAER    POLYTECHNIC    INSTITUTE. 


SECOND  EDITION, 
REVISED  AND   GREATLY  ENLARGED. 


PHILADELPHIA : 
PUBLISHED  BY  T.  ELLWOOD  ZELL, 

NO.  439  MARKET  STREET. 

1861. 


££ 


VN. 


Entered,  according  to  Act  of  Congress,  in  the  year  1860, 

BY   WILLIAM    ELDERHORST, 
In  the  Clerk's  -Office  of  the  District  Court  for  the  Northern  District  of  New  York. 


PREFACE. 


* 

THE  present  edition  of  this  ''Manual,"  is,,like  the  preceding,  designed 

to  serve  as  a  text-book  in  the  instruction  in  Blowpipe- Analysis  and  De- 
terminative Mineralogy  in  the  Rensselaer  Polytechnic  Institute. 

In  the  first  three  chapters,  but  few  alterations  and  additions  have  been 
made,  fearful  of  injuring  the  practical  usefulness  of  the  book  by  an  accu- 
mulation of  too  much  material.  The  fourth  chapter,  containing  the 
characteristics  of  the  most  important  ores,  hasj^een  considerably  enlarged 
by  increasing  the  number  of  species,  and  by^  adding  an  appendix  con- 
taining the  description  and  blowpipe  reactions  of  the  various  kinds  of 
fossil  fuel ;  additions  which,  I  trust,- will  be  especially  acceptable  to  the 
Mining-Engineer  and  Geologist.  In  the  selection  'of  the  newly  added 
species  I  have  paid  particular  regard  to  those  occurring  in  the  American 
Continent ;  for  this  reason,  many  less  important  ores  have  found  a  place 
in  the  list  to  the  exclusion  of  others,  which,  though  more  valuable,  have 
not  hitherto  been  found  in  America. 

The  fifth  chapter,  containing  a  systematic  method  for  the  discrimina- 
tion of  inorganic  compounds,  is  a  translation,  but  slightly  altered,  of  the 
" Division  dichotomique  pour  reconnoitre  les  minfraux,"  as  given  in 
Laurent's  "Analyze  au  Chalumeau"  It  is  of  no  great  value  to  the 
experienced  analyst,  but  very  useful  for  beginners,  and  it  is  on  their 
account  that  I  have  given  it  a  place  in  the  Manual. 

The  sixth  chapter  is  not  contained  in  the  first  edition.  It  is  hardly 
necessary  to  allege  any  reason  for  its  introduction  into  this  edition. 
The  admirable  method  of  Professor  von  Kobell  for  the  discrimination 


IV 


of  minerals  is,  almost  beyond  dispute,  the  most  practical  and  most  relia- 
ble that  has  ever  been  published.  The  sixth  chapter  is  nothing  but  an 
extract  from  Prof.  v.  Kobell's  treatise  on  this  subject.  It  contains  all 
the  well-known  mineral  species,  and  leads  to  their  determination  with 
almost  unerring  certainty. 

The  appended  tables,  taken  from  Plattner's  work  on  the  Blowpipe, 
have  remained  unchanged. 

For  the  material  of  this  compilation,  the  author  is  principally  in- 
debted to  the  following  works  : 

C.  F.  Plattner:  The  Use  of  the  Blowpipe  in  the  Examination  of  Mi- 
nerals, Ores,  &c.     Translated  by  J.  S.  Musprath,  3d  ed.,  London. 

J.  J.  Berzelius :    The  Use  of  the  Blowpipe  in  Chemistry  and  Mine- 
ralogy.    Translated  by  J.  D.  Whitney,  Boston. 

F^  von  Kobell:    Tafeln  zur  Bestimmung  der  Mineralien.      5th  ed. 
Munchen.  1853. 

J.  D.  Dana:  A  System  of  Mineralogy.     4th  ed.,  New  York,  1854. 

John  Mitchell:  Manual  of  Practical  Assaying.     2d  ed.,  Lond.,  1854. 

The  author,  finally,  begs  to  tender  his  thanks  to  his  friend,  Professor 
Chandler,  of  Union  College,  for  the  valuable  suggestions  he  has  received 
at  his  hands,  and  which  he  has  acted  upon  to  the  best  of  his  ability, 
being  fully  convinced  that  by  adding  the  improvements  recommended  by 
his  friend,  the  practical  utility  of  this  little  Manual  will  be  greatly  in- 
creased. 

WILLIAM  ELDERHORST. 

TROY,  N.  Y.,  March,  1860. 


INTRODUCTION. 


IN  preparing  this  little  Manual,  it  has  been  my  principal  care  to  adapt 
it  to  the  use  of  the  beginner.  The  use  of  the  blowpipe,  though  elabo- 
rately studied  and  extensively  written  on  by  some  of  the  first  chemists 
and  mineralogists  of  the  preceding  and  the  present  century,  has  not  yet 
been  duly  appreciated.  This  neglect  is,  perhaps,  owing  to  the  rapid  ad- 
vancement of  chemical  analysis  in  the  humid  way,  which  furnishes,  on 
the  whole,  more  reliable  results,  and  allows  of  an  easy  quantitative  deter- 
mination of  the  various  constituents  of  a  body.  But  it  was  overlooked 
that  this  mode  of  analysis  absorbs  much  more  time,  and  requires  the 
use  of  an  extensive  set  of  apparatus,  whereas  an  examination  before  the 
blowpipe  is  sooner  performed ;  requiring  scarcely  as  many  hours  as  an 
examination  in  the  humid  way  requires  days,  and  that,  with  the  aid 
only  of  a  few  reagents  and  instruments  of  small  size.  It  is  for  this 
reason  that  a  knowledge  of  blowpipe-operations  is  less  valuable  for  the 
Chemist  by  profession  than  for  the  Mining-Engineer,  the  Mineralogist, 
and  the  Geologist.  A  small  portable  box  will  hold  all  the  necessary 
reagents  and  instruments,  so  that  he  may  carry  them  with  him  on  his 
expeditions  and  travels,  and  examine  on  the  spot  the  minerals  which  he 
meets  with  on  his  explorations  j  an  advantage  which  ought,  truly,  not  to 
be  overlooked. 

For  teachers  who  have  not  hitherto  devoted  much  time  to  instruction 
in  this  department,  a  short  exposition  of  the  course  which  I  have  fol- 
lowed for  a  number  of  years  may,  perhaps,  be  desirable.  For  elemen- 
tary instruction,  the  students  are  only  famished  with  the  principal  re- 


vi 


agents,  viz ,  carbonate  of  soda,  salt  of  phosphorus,  borax,  and  solution 
of  cobalt ;  of  apparatus  they  want  a  fluid-lamp,  blowpipe  with  platinum 
point,  platinum-pointed  forceps,  platinum  wire,  charcoal,  and  closed  and 
open  glass-tubes.  After  having  explained  to  them  the  action  of  the 
two  cones  of  the  flame,  and  instructed  them  in  making  beads,  and  con- 
ducting the  processes  of  oxidation  and  reduction,  I  make  them  perform 
the  most  important  operations,  and  study  the  behavior  of  the  most  com- 
monly occurring  substances,  with  and  without  fluxes.  I  give  the  sub- 
stances in  somewhat  the  following  order : 

Sesquioxide  of  iron,  all  the  reactions  given  in  Table  II,  10. 

Peroxide  of  manganese,  Table  II.  13. 

Sesquioxide  of  chromium,  Table  II,  6. 

Oxide  of  cobalt,  and  nickel,  Table  II,  7,  16. 

Protoxide  of  copper,  Table  II,  8,  and  §  37. 

Oxide  of  zinc,  Table  II,  27,  and  metallic  zinc  \\  25,  45. 

Oxide  of  tin,  Table  II,  22,  and  metallic  tin  I  26. 

Oxide  of  lead,  Table  II,  12,  and  metallic  lead  $  23. 

Oxide  of  bismuth,  Table  II,  3,  and  metallic  bismuth  $  17,  22. 

Antimonous  acid,  Table  II,  1,  and  metallic  antimony  $$  16,  21. 

Arsenous  acid,  Table  II,  2,  $$  9,  15. 

Oxide  of  mercury,  Table  II,  14. 

Alumina,  Table  I,  5,  and  \  44. 

Magnesia,  Table  I,  4,  and  \  44. 

Silica,  g  39. 

A  sulphide,  \\  10,  14,  107. 

A  borate,  g  60. 

A  chloride,  g|  65,  66. 

Having  performed  all  these  operations,  the  student  will  ba  qualified  to 
enter  upon  the  analysis  of  substances  of  not  too  compound  a  character. 
If  he  meets  on  his  way  with  bodies,  the  behavior  of  which  before  the 
blowpipe  he  has  not  previously  studied,  he  will  not  have  any  difficulty  in 
determining  their  character  if  he  follows  the  directions  given  in  the 
second  chapter.  The  modus  operandi  will  be  best  understood  by  a  few 
examples. 


Vll 


1.  The  substance  under  examination  is  sulphide  of  antimony : 
Examination  in  a  matrass  :  At  a  very  high  temperature,  a  black  subli- 
mate is  obtained,  becoming  reddish-brown  when  cold.     In  reading  over 
the  list  in  g  10  we  find  this  character  belonging  to  sulphide  of  antimony. 

Examination  in  an  open  glass-tube :  gives  sulphurous  acid,  detected 
by  the  odor  and  action  on  blue  litmus-paper,  and  white  fumes  which 
partly  condense  in  the  tube.  On  examining  the  sublimate  with  a  mag- 
nifying glass,  it  is  found  to  be  amorphous,  hence  must  be  antimonous 
acid  (g  16). 

Examination  on  charcoal  alone :  is  completely  volatilized  with  emis- 
sion of  sulphurous  acid,  and  deposits  a  white  volatile  coating,  possessing 
the  properties  of  the  coating  of  antimony  (§  21). 

These  few  operations  are  quite  sufficient  to  establish  the  nature  of  the 
substance  under  trial,  since  the  absence  of  the  more  fixed  metals  is 
proved  by  the  volatility  of  the  substance  on  charcoal  and  in  the  open 
tube,  and  the  absence  of  metals  giving  coatings  by  the  purity  of  the 
antimony-coating.  The  presence  of  arsenic  would  have  been  betrayed 
by  an  alliaceous  odor  when  heated  on  charcoal.  The  only  substance 
which  would  have  escaped  detection  by  these  operations  is  sulphide  of 
mercury.  In  order  to  ascertain  its  presence  or  absence,  we  perform  the 
operation  given  under  "  Mercury'1''  in  Chapter  III. 

The  result  giving  an  answer  in  the  negative,  the  body  was  "sulphide 
of  antimony." 

2.  The  substance  under  examination  is  chromate  of  lead. 

Examination  in  a  matrass :          "I  fuses  and   changes   color,  but   gives 
Examination  in  an  open  tube  :    /      nothing  volatile. 

Examination  on  charcoal  alone :  fuses,  gives  small  metallic  globules, 
and  deposits  a  coating  which  is  lemon-yellow  while  hot,  and  sulphur- 
yellow  when  cold,  indicative  of  lead  ($  23).  It  is  always  desirable  to 
collect  the  metal  to  a  large  globule,  and  to  study  its  physical  properties. 
This  end  is  best  attained  by  mixing  the  substance  with  carbonate  of 
soda  and  a  little  borax,  and  exposing  the  mixture  to  the  reduction-flame 
on  charcoal.  In  this  particular  case,  a  metallic  button  is  obtained  which 


Vlll 


is  soft,  may  be  flattened  by  the  hammer  and  cut  by  the  knife,  properties 
belonging  to  metallic  lead. 

Examination  with  borax  and  salt  of  phosphorus :  Before  proceeding 
with  this  examination  it  is  necessary  to  test  the  substance  for  the  pre- 
sence of  sulphur  after  the  method  given  $  107  (unless  the  presence  of 
this  element  was  detected  by  the  examination  in  the  open  glass-tube  or 
on  charcoal  alone)  ;  no  sulphur  being  present,  borax  and  salt  of  phos- 
phorus beads  are  made  on  charcoal,  and  small  portions  of  the  substance 
added.  With  both  fluxes  nearly  the  same  reactions  are  obtained ;  in 
oxydation-flame  dark  red  while  hot,  and  fine  yellowish-green  when  cold  ; 
in  reduction-flame  green,  hot  and  cold.  In  order  to  find  out  what  body 
produces  such  reactions,  we  use  Table  III,  which  leads  us  to  sesquioxide 
of  chromium.  To  corroborate  the  result,  the  substance  may  be  fused 
with  carbonate  of  soda  and  nitre,  as  described,  $  68. 

The  physical  properties  of  the  body  under  trial  lead  to  the  final  con- 
clusion that  it  must  be  chromate  of  lead. 

3.  The  substance  is  an  alloy  of  silver,  copper,  and  lead. 
Examination  in  a  matrass : 


no  change. 
Examination  in  an  open  tube 

Examination  on  charcoal  alone :  fuses  and  deposits  a  copious  coating, 
which  is  lemon-yellow  while  hot  and  sulphur-yellow  when  cold,  indicative 
of  lead  ($  23) ;  the  coating  cannot  contain  any  oxide  of  bismuth,  be- 
cause the  color  would  be  darker  in  this  case,  but  might  contain  oxide  of 
zinc  or  oxide  of  antimony.  To  test  it  for  the  presence  of  the  former, 
the  coating  is  played  upon  with  the  oxydation-flame :  it  is  completely 
volatile,  hence  no  zinc  present  (might  also  be  tested  with  solution  of 
cobalt  g  45) ;  to  test  the  coating  for  the  presence  of  oxide  of  antimony, 
it  is  scraped  off  from  the  charcoal  and  dissolved  in  a  bead  of  salt  of 
phosphorus,  v.  §  87,  or  the  alloy  is  treated  with  boracic  acid  as  described 
under  the  head  of  "  Antimony"  in  Chapter  III.  If  the  blast  is  con- 
tinued for  a  long  time,  a  faint  dark  red  coating  is  formed  near  the  assay- 
piece,  indicative  of  silver  $  27,  and  a  dark  metallic  globule  remains. 

Examination  with  borax  and  salt  of  phosphorus:  the  globule  remain- 
ing on  the  charcoal  after  volatilization  of  the  lead,  is  treated  with  borax 


on  charcoal  in  oxidation-flame;  the  borax  becomes  colored.  Owing  to 
the  reducing  effect  of  the  charcoal,  the  influence  of  the  oxidation-flame 
cannot  be  well  observed  on  charcoal,  hence  the  borax  is  removed  from 
the  metallic  globule,  fastened  into  the  hook  of  a  platina  wire,  and  here 
exposed  to  the  action  of  the  oxidation-flame :  the  bead  is  green  while 
hot,  and  blue  when  cold.  On  consulting  Table  III  we  find  that  this  re- 
action is  produced  by  oxide  of  copper,  and  by  a  mixture  of  oxide  of 
cobalt  and  sesquioxide  of  iron  :  to  decide  between  the  two,  we  now 
expose  the  bead  to  the  action  of  the  reduction-flame;  it  becomes  red  and 
opaque,  thus  proving  the  presence  of  oxide  of  copper. 

By  the  examination  on  charcoal,  per  se,  we  were  led  to  suspect  the 
presence  of  silver ;  in  order  to  establish  this  beyond  a  doubt,  we  refer  to 
Chapter  III,  "Silver;"  here  we  find  a  method  ($  105)  by  which  the  pre- 
sence of  silver  may  be  ascertained  in  compounds  of  all  descriptions. 
In  our  case,  having  to  deal  only  with  lead,  copper,  and  silver,  the  treat- 
ment with  vitrified  boracic  acid  and  metallic  lead  is,  of  course,  super- 
fluous. We  place  our  alloy  at  once  on  the  cupel  and  direct  the  oxidation- 
flame  upon  it;  if,  after  cessation  of  the  rotatory  motion,  the  globule 
should  not  possess  the  bright  lustre  of  silver,  some  pure  metallic  lead 
has  to  be  added,  in  order  to  remove  the  last  traces  of  copper.  We  finally 
obtain  a  bright  globule  exhibiting  all  the  characteristic  properties  of 
silver. 

Thus  we  have  established  the  presence  of  lead,  copper,  and  silver. 

4.  The  substance  under  examination  is  copper  nickel,  containing 
arsenic,  sulphur,  nickel,  cobalt,  and  iron. 

Examination  in  a  matrass:  gives  a  slight  sublimate,  consisting  of 
octahedral  crystals,  pointing  to  the  presence  of  arsenic  (§  11). 

Examination  in  a  glass  tube  open  at  both  ends :  gives  a  copious  crys- 
talline sublimate  of  arsenous  acid,  and  a  faint  odor  of  sulphurous  acid  ; 
to  establish  the  presence  of  sulphur  beyond  doubt,  we  refer  to  Chapter 
III,  "Sulphur,-"  where  we  find  the  method  (§  107)  for  discovering  sul- 
phur when  in  combination  with  other  substances.  In  performing  the  test 
there  described,  we  obtain  the  sulphur-reaction. 

Examination   on   charcoal  alone  :  gives  abundant  arsenical  fumes, 


leaving  a  metallic  globule  which,  even  with  continued  blowing,  does  not 
give  rise  to  the  formation  of  a  coating  on  the  charcoal  (absence  of  vola- 
tile metals). 

Having  removed  all  volatile  substances,  we  now  proceed  to  examine 
the  remaining  globule.  On  applying  a  magnet,  we  find  it  powerfully 
attracted,  showing  the  presence  of  either  iron,  nickel,  or  cobalt,  perhaps 
all  of  them,  either  alone  or  combined  with  other  non-volatile  metals. 
We  add  some  borax  to  the  globule  and  expose  it  to  the  action  of  the 
oxidation-flame,  then  remove  the  borax  from  the  globule,  fasten  it  into 
the  hook  of  a  platina  wire,  and  here  observe  the  color :  green  while  hot, 
blue  when  cold  as  in  the  preceding  case  (example  3),  but  on  exposing 
the  bead  to  the  action  of  the  reduction-flame  (which  is  best  done  by 
placing  it  on  charcoal  and  touching  it  with  tin)  it  does  not  become  brown 
and  opaque,  showing  therefore  the  presence  of  a  small  quantity  of  iron 
with  cobalt.  We  now  add  a  fresh  portion  of  borax  to  the  metallic  glo- 
bule, in  order  to  see  whether  it  consists  entirely  of  cobalt  (that  it  cannot 
contain  any  considerable  amount  of  iron,  is  proved  by  the  appearance  of 
the  cobalt  reaction  in  the  first  trial,  iron  being  much  more  readily  dis- 
solved by  borax  than  cobalt) :  the  bead  is  violet  while  hot,  and  assumes 
a  brownish  color  on  cooling ;  by  referring  to  Table  III,  we  see  that  this 
effect  is  produced  by  nickel  containing  cobalt.  Referring  to  Chapter  III, 
"  Nickel,"  we  find  the  method  to  detect  the  presence  of  this  metal  when 
in  combination  with  iron  and  cobalt,  and  also  the  presence  of  copper,  if 
the  assay  should  contain  a  small  quantity  of  it. 

By  the  above  examples  the  use  of  the  methods  given  in  the  third 
chapter  will  be  sufficiently  illustrated.  If  the  substance  under  examina- 
tion is  of  a  simple  composition,  its  nature  is  readily  ascertained  by  fol- 
lowing the  general  method  laid  down  in  the  second  chapter ;  but  if  the 
reactions  obtained  clearly  point  to  the  complex  nature  of  the  body,  we 
refer  to  the  respective  sections  of  Chapter  III ;  if,  for  example,  we  sus- 
pect the  presence  of  cobalt  in  a  mineral  consisting  of  arsenides,  we  test 
the  substance  according  to  §  69  ;  if  a  small  quantity  of  copper  is  to  be 
discovered  in  a  mineral,  we  proceed  as  directed  in  $  71,  &c. 

The  student  who  is  willing  to  devote  more  time  to  the  subject  than  is 


XI 

usually  allotted  to  it  in  our  colleges,  will  do  well  to  go  carefully  through 
all  the  reactions  given  in  the  second  chapter,  and  thus  familiarize  himself 
with  the  colors  and  other  properties  of  the  various  coatings,  sublimates, 
&c.,  and  also  to  perform  the  principal  tests  by  which  substances  are 
discovered  when  in  combination  with  others,  which  are  at  length  exposed 
in  the  third  chapter.  In  order  to  obtain  characteristic  reactions,  it  is 
important  to  experiment  upon  a  suitable  substance.  For  the  benefit  of 
the  beginner,  who  would  naturally  be  embarrassed  in  the  choice  of  a 
body  suitable  for  the  experiment,  I  add  a  list  of  substances  which,  with 
few  exceptions,  are  readily  obtained,  and  which  are  sufficient  to  illustrate 
all  the  important  reactions.  After  having  mentioned  a  reaction,  or  de- 
scribed a  process  (in  Chapter  II  and  III),  I  have  added  a  number  in  [  ] 
brackets.  The  number  points  to  the  substance  of  the  list,  below  given, 
best  adapted  to  illustrate  the  reaction.  As  each  experiment  requires  only 
a  very  small  quantity  of  the  substance,  they  are  most  conveniently  kept 
in  small  glass-tubes  of  about  an  inch  and  a  half  in  length  and  one-eighth 
of  an  inch  in  diameter.  For  the  first  fourteen  substances  no  glass-tubes 
are  required,  since  they  are  the  regular  blowpipe  reagents.  A  small  box 
containing  seventy-five  of  the  little  tubes  will  hold  the  whole  collection. 


Xll 


COLLECTION   OF   SUBSTANCES, 

Well  adapted  to  illustrate  the  important  reactions  of  bodies  before 
tlie  blowpipe. 


1.  Carbonate  of  soda. 

2.  Borax. 

3.  Salt  of  phosphorus. 

4.  Bisulphate  of  potassa. 

5.  Boracic  acid. 

6.  Fluor  spar. 

7.  Nitrate  of  cobalt. 

8.  Oxalate  of  nickel. 

9.  Oxide  of  copper. 

10.  Chloride  of  silver. 

11.  Lead. 

12.  Iron. 

13.  Tin. 

14.  Bone-ash. 

15.  Chloride  of  potassium. 

16.  Bromide  of  potassium. 

17.  Iodide  of  potassium. 

18.  Chloride  of  sodium. 

19.  Chloride  of  ammonium. 

20.  Chlorate  of  potassa. 

21.  Alumina. 

22.  Sulphate  of  copper. 

23.  Nitrate  of  lead. 

24.  Oxide  of  antimony. 

25.  Arsenous  acid. 

26.  Oxide  of  bismuth. 

27.  Oxide  of  cadmium. 


28.  Sesquioxide  of  chromium. 

29.  Oxide  of  cobalt. 

30.  Protoxide  of  mercury. 

31.  Molybdic  acid. 

32.  Oxide  of  silver. 

33.  Binoxide  of  tin. 

34.  Tungstic  acid. 

35.  Sesquioxide  of  uranium. 

36.  Oxide  of  zinc. 

37.  Chloride  of  copper. 

38.  Arsenite  of  copper. 

39.  Subchloride  of  mercury. 

40.  Protochloride  of  mercury. 

41.  Antimony. 

42.  Arsenic. 

43.  Bismuth. 

44.  Cadmium. 

45.  Silver. 

46.  Zinc. 

47.  Alloy  of  mercury  and  tin. 

48.  Alloy  of  lead  and  antimony. 

49.  Alloy  of  lead  and  bismuth. 

50.  Alloy  of  lead  and  zinc. 

51.  Alloy  of  lead,  copper  and  silver. 

52.  Alloy  of  tin  and  copper. 

53.  Alloy  of  zinc  and  cadmium. 

54.  Rock  crystal. 


Xlll 


55. 

Gypsum. 

74. 

56. 

Calc-spar. 

75. 

57. 

Strontianite. 

76. 

58. 

Whitherite. 

77. 

59. 

Magnesite. 

78. 

GO. 

Mica. 

79. 

61. 

Felspar. 

80. 

62. 

Albite. 

81. 

63. 

Petalite. 

82. 

64. 

Hematite. 

83. 

65. 

Rutile. 

84. 

66. 

Pyrolusite. 

85. 

67. 

Lepidolite. 

86. 

68. 

Apatite. 

87. 

69. 

Franklinite. 

88. 

70. 

Pitchblende. 

71. 

Chromic  iron. 

89. 

72. 

Cerusite. 

73. 

Malachite. 

Gray  antimony. 

Iron  pyrites. 

Copper  pyrites. 

Mispickel. 

Smaltine. 

Cobaltine. 

Realgar. 

Cinnabar. 

Copper  nickel. 

Molybdenite. 

Berthierite. 

Bournonite. 

Tetrahedrite. 

Onofrite,  or  Clausthalite. 

Sulphides  of  arsenic  and  anti- 
mony (artificial) . 

Sulphides  of  arsenic,  antimony, 
lead,  and  copper  (artificial). 


TABLE  OF  CONTENTS. 


TAGE 

Preface,  .......  iii 

Introduction,         .  •.  •.'•.*          .  .  v 

List  of  substances  serving  to  illustrate  the  reactions,  .  xii 


FIRST  CHAPTER. 

AUXILIARY  APPARATUS  AND  REAGENTS,  .     ,  ,%      13 — 16 

SECOND  CHAPTER. 

GENERAL  ROUTINE  OF  BLOWPIPE  ANALYSIS,  .  .   ...        .        17 — 31 

Examination  in  a  closed  glass  tube,  .  •.  18 

Examination  in  a  glass  tube  open  at  both  ends,  .        21 

Examination  on  charcoal,  per  se,     «          ..  ..^  22 

Examination  in  the  platinum-pointed  pincers,     .  .        24 

Examination  with  borax  and  salt  of  phosphorus,     ,   ,  27 

Examination  with  carbonate  of  soda,      .  .  .28 

Examination  with  solution  of  cobalt,  .  .  30 


XVI 


THIRD  CHAPTER. 

PAGE 

SPECIAL  REACTIONS  FOR  THE  DETECTION  OF  CERTAIN  SUB- 
STANCES  WHEN   IN   COMBINATION   WITH   OTHERS,       .  32 54 

Ammonia,     .  .          '  *     '       .„  '        "  ",  '          .  33 

Antimony,  .  .  .  .  .  .33 

Arsenic,        fc'l        .  .  .  j[ »  34 

Bismuth,  .....  ,.        36 

Boracic  acid,  .....  30 

Bromine,  *  •  , .  .  .        37 

Cadmium,      ......  37 

Chlorine,  .         '    .^        <  *    '         .  .  .37 

Chromium,     .  .  .  .  .  .  38 

Cobalt,      .  .'  .'  .'          •  '          .*  .        38 

Copper,          .'••     '-••^'":    '***,***    ^f*^    S^*1      *'!?i'  39 

Fluorine,  .  .  .  .  :  ,41 

Gold,  .  .    t      _   .  *  .      f   .  .  42 

Iodine,     .  .     -    *•*•  ^        *.    '    •***•*•         .  .        43 

Iron,  ......  43 

Lead,       .  .-  .»  t    ^i'^      ^**     JT4H^-    f'-  ,^'     44 

Lithia,  ......  45 

Manganese,          .  .  •  '          •  r         •  *        46 

Mercury,        .  .          -*•*•/••-'     -    ;---     »  .-*          .  46 

Nickel,    .......  i  .        46 

Nitric  acid,    .  *  ':         .  .  .  .  47 

Phosphoric  acid,  .  .  .  .  .47 

Potassa,        /'*  .  .  48 

Selenium,  /  .  .  •  •  .48 

Silica, 49 

Silver, 49 

Sulphur,        .  .  .  .  .  .  51 

Tellurium,  ......         52 


XV11 


PAGE 


Tin,  . 

Titanium, 
Uranium, 
Zinc, 


52 
53 
53 
54 


FOURTH  CHAPTER. 

CHARACTERISTICS  OP  THE  MOST  IMPORTANT  ORES  j  THEIR  BE- 
HAVIOR  BEFORE   THE   BLOWPIPE,   AND  TO   SOLVENTS,  55 — 91 

Ores  of  antimony,                          .             .             .             .  56 

arsenic,           ......  58 

bismuth,              ..  "           .-            ."           .             .  59 
chromium,     .            »            ,            .             .            .60 

cobalt,      .             .            .            .            ..            .  61 

copper,  .  .  .  .  .  .63 

gold,  platinum,  and  iridium,         ...  68 
iron,  .             ,             .             .             .             .             .69 

lead,        .•            $&        .            .         '  .            .  73 

manganese,    .             .             .            .           :  .             .  79 

mercury,               .            .            .             .            .  80 

nickel,           .            .            .        /  ,  81 

silver,      .            .            .            ,            .            .  83 

tin,     .            .            .                         ....  87 

zinc,        .            .-           .            .            .            .  88 

APPENDIX — Fossil  fuel,          .....  90 

FIFTH  CHAPTER. 

SYSTEMATIC   METHOD   FOR  THE   DISCRIMINATION    OF   INOR- 
GANIC COMPOUNDS,  .....  92 — 105 

SIXTH  CHAPTER. 

ON   THE    DISCRIMINATION   OF    MINERALS    BY   MEANS    OF     THE 

BLOWPIPE,    AIDED    BY   HUMID    ANALYSIS,         .                  .  106 — 141 


XV111 


TABLES. 

PACK 

TABLE  I. — BEUAVTOR  OF  THE  ALKALINE  EARTHS  AND  THE 

EARTHS  PROPER  BEFORE  THB  BLOWPIPE,      .  .  144 — 147 

TABLE  II. — BEHAVIOR  OF  THE  METALLIC  OXIDES  BEFORE 

THE  BLOWPIPE,          .....  148 — 161 

TABLE  III. — THE  METALLIC  OXIDES  ARRANGED  WITH  RE- 
FERENCE   TO    THE  COLORS  WHICH    THEY  IMPART  TO   THE 

FLUXES,        ......  162—167 


ABBREVIATIONS. 


OF1  for  Oxydation-flarae ;  RF1  for  Reduction-flame ;  SPh  for  Salt  of 
Phosphorus ;  Bx  for  Borax ;  Sd  for  Carbonate  of  Soda;  SoCo  or  SCo  for 
Solution  of  Nitrate  of  Cobalt;  Ch  for  Charcoal;  Ct  for  Coating;  Blp  for 
Blowpipe  ;  H  for  Hardness  ;  G  for  Specific  Gravity. 


FIRST  CHAPTER, 


AUXILIARY  APPARATUS  AND  REAGENTS. 

1 1.  THE  common  blowpipe  of  gas-fitters,  jewellers,  &c.,  is  not  very 
well  adapted  for  analytical  researches,  as  the  narrow  outlet  becomes  fre- 
quently obstructed  by  the  moisture  which  is  exhaled  from  the  lungs  and 
condenses  in  the  tube.  To  avoid  this  inconvenience,  the  long  cylindrical 
tube  of  the  blow-pipe  should  be  furnished  at  the  extremity  with  a  globu- 
lar or  cylindrical  chamber  for  the  reception  of  the  condensed  water.  In 
this  chamber  the  jet  is  inserted  at  a  right  angle  to  the  tube.  Silver  is, 
in  many  respects,  the  best  material  for  the  construction  of  a  blow-pipe, 
but  has  the  disadvantage  of  becoming  very  hot  when  used  for  a  long 
while,  so  that  it  becomes  almost  impossible  to  hold  it  with  the  naked 
fingers ;  next  to  silver  stands  German  silver  and  brass.  For  jets,  plati- 
num is  preferable  to  all  other  metals.  A  mouth-piece  of  box-wood  or 
ivory  is  convenient,  though  not  necessary. 

\  2.  Any  kind  of  flame  may  be  used  for  the  blowpipe,  provided  it  be 
not  too  small.  Some  of  the  older  chemists  used  common  candles  in  pre- 
ference, and  it  must  be  confessed  that,  in  the  majority  of  cases,  the  heat 
produced  by  the  flame  of  a  good  sperm  candle  is  quite  sufficient.  Berze- 
lius  recommended  an  oil  lamp  with  a  flat  wick,  which  is  now  in  general 
use  as  "  Berzelius's  Blowpipe  Lamp."  I  find  that  a  common  fluid  lamp, 
with  a  rather  large  burner,  answers  every  purpose  ;  it  gives  a  very  good 
heat,  and,  besides  being  much  cleaner  than  an  oil  lamp,  admits  of  a  very 

2 


14 


quick  and  accurate  adjustment  of  the  size  of  the  flame,  by  means  of  a 
little  brass  cylinder,  which  is  movable,  and  slides  up  and  down  the 
burner.  The  heating  of  substances  in  glass  tubes  and  matrasses  is  best 
performed  over  a  common  spirit  lamp. 

$  3.  As  supports,  charcoal,  platinum,  and  glass  are  principally  used. 
Wood  charcoal  is  in  most  cases  the  best  support.  It  must  be  well  burnt, 
and  not  scintillate  or  smoke ;  it  must  leave  but  little  ash ;  charcoal  of 
light  wood,  as  alder,  &c.,  has  been  found  the  best. 

Platinum  is  used  whenever  the  reducing  action  of  the  charcoal  acts 
injuriously.  It  is  advantageously  employed  on  all  occasions  where  no 
reduction  to  the  metallic  state  takes  place,  since  the  color  of  the  flux  is 
much  better  seen  on  the  platinum  than  on  charcoal.  It  is  mostly  used 
in  the  shape  of  wire,  the  end  of  which  is  bent  so  as  to  form  a  hook,  which 
serves  as  support  to  the  flux.  As  foil,  its  use  is  very  limited.  A  little 
platinum  spoon,  of  from  about  12  to  15  m.  m.  in  diameter,  is  very  con- 
venient for  fusing  substances  with  bisulphate  of  potassa  or  nitre. 

Glass  tubes,  open  at  both  ends,  are  used  for  calcination,  and  for  test- 
ing the  presence  of  substances  which  are  volatile  at  a  high  temperature. 
The  tubes  should  be  from  5  to  8  inches  long.  Of  glass  tubes,  sealed  at 
one  end,  or  little  matrasses,  an  assortment  should  always  be  kept  on 
hand,  since  they  are  of  very  frequent  use. 

I  4.  Of  other  apparatus,  the  most  necessary  are  : 

A  mortar  of  agate  or  chalcedony,  from  1J  to  2  inches  in  width,  with 
pestle  of  the  same  material. 

A  forceps  of  brass  or  German  silver,  with  platinum  points. 

A  forceps  of  steel. 

A  little  hammer  and  anvil,  both  of  steel  and  well  polished. 

A  three-cornered  file  for  cutting  glass  tubes,  trying  the  hardness  of 
minerals,  &c. 

A  little  magnet. 

A  pocket  magnifying  glass. 

A  set  of  watch  glasses,  which  are  very  convenient  for  the  reception  of 
the  assay-piece,  the  metallic  globules,  &c. 

g  5.  Of  reagents,  Carbonate  of  Soda,  Borax,  and  Salt  of  Phosphorus, 


15 


are  the  most  important  ones  ;  but  there  are  others,  which,  though  not  so 
extensively  used,  still  are  indispensable  for  the  detection  of  certain  sub- 
stances ;  those  only  shall  here  be  mentioned ;  others,  the  use  of  which  is 
very  limited,  are  omitted  in  this  list. 

Carbonate  of  Soda  :  The  monocarbonate  or  the  bicarbonate  may  be 
indifferently  employed  ;  it  must  be  perfectly  free  from  sulphuric  acid,  for 
the  presence  of  which  it  may  be  tested  as  shown  $  107.  The  neutral 
oxalate  of  potassa  and  the  commercial  [fused]  cyanide  of  potassium 
deserve  in  many  cases  the  preference,  their  reducing  powers  being  supe- 
rior to  that  of  carbonate  of  soda. 

Borax :  The  commercial  article  is  purified  by  crystallization,  the 
crystals  dried  and  reduced  to  a  coarse  powder. 

Salt  of  Phosphorus  :  [double  phosphate  of  soda  and  ammonia]  100 
parts  of  crystallized  common  phosphate  of  soda  and  16  parts  of  sal  am- 
moniac are  dissolved  in  32  parts  of  water  ;  the  solution  is  aided  by  heat, 
the  liquid  filtered  while  hot,  and  the  crystals,  which  form  on  cooling, 
dried  between  blotting  paper.  When  pure  it  gives  a  glass  which,  on 
cooling,  remains  transparent;  if  this  is  not  the  case  it  must  be  purified 
by  recrystallization.  It  is  kept  as  a  coarse  powder. 

Bisulphate  of  Potassa  :  It  is  employed  in  the  fused  [anhydrous]  state 
as  a  coarse  powder ;  it  must  be  kept  in  a  bottle  provided  with  a  ground 
glass  stopper. 

Vitrified  Boracic  Acid  :  Is  employed  in  the  state  of  a  coarse  powder. 

Fluor-spar  :  Must  be  deprived  of  water  by  ignition  ;  must  be  perfectly 
free  from  boracic  acid,  which  may  be  tested  as  described  \  61.  It  is 
convenient,  to  keep  in  a  separate  bottle  a  mixture  of  1  part  of  finely 
powdered  fluor-spar  with  4£  parts  of  bisulphate  of  potassa. 

Nitrate  of  Cobalt,  in  solution  :  It  must  be  pure,  free  from  alkali,  and 
[for  many  purposes]  free  from  nickel ;  it  is  kept  in  a  bottle  with  a  ground 
glass  stopper,  which,  very  conveniently,  is  so  much  elongated  as  to  dip 
into  the  liquid.  Instead  of  the  nitrate,  the  oxalate  of  cobalt  may  be 
used,  which,  being  in  the  shape  of  powder,  is  advantageously  substituted 
for  the  former  in  travelling. 

Nitrate  or  Oxalate  of  Nickel :  It  must  be  perfectly  free  from  cobalt ;  it 


16 


is  tested  with  borax,  with  which  it  ought  to  produce  a  pure  brown 
glass. 

Oxide  of  Copper :  It  is  best  prepared  by  heating  the  nitrate  to  ignition. 

Chloride  of  Silver :  It  is  prepared  by  precipitating  a  solution  of  nitrate 
of  silver  with  hydrochloric  acid,  washing  the  precipitate,  and  making  it 
into  a  thick  paste  with  water,  which  is  kept  in  a  small  glass-stoppered 
bottle.  This  reagent  should  not  be  used  with  platina  wire,  since  the 
silver  fuses  with  the  platina  to  an  alloy  j  thin  iron  wire  is  in  this  case 
substituted  for  the  platina.  For  each  experiment  a  fresh  hook  should 
be  made. 

Pure  Metallic  Lead :  It  is  easily  obtained  pure  by  decomposing  a  solu- 
tion of  the  acetate  by  metallic  zinc;  the  precipitate  is  repeatedly  washed 
with  water  and  then  dried  between  blotting  paper. 

Metallic  Iron  :  In  the  shape  of  thin  wire  [harpsichord  wire]. 

Metallic  Tin :  Usually  in  the  shape  of  foil,  which  is  cut  into  stripes 
and  rolled  up  tightly. 

Bone-ash :  In  the  state  of  very  fine  powder. 

Test  Paper :  Blue  and  red  Litmus  Paper,  and  Brazil  Wood  Paper. 

$  6.  If  the  analytical  research  is  strictly  confined  to  blowpipe  opera- 
tions, the  above  enumerated  reagents  are  sufficient;  but  if,  as  is  some- 
times advantageously  done,  some  simple  operations  of  the  humid  method 
of  chemical  analysis  are  called  to  aid,  the  list  must  be  somewhat  ex- 
tended. The  most  important  of  these  reagents,  all  of  which  must  be 
kept  in  bottles  with  ground  glass  stoppers,  are:  Sulphuric  Acid,  Hydro- 
chloric Acid,  Nitric  Acid,  Oxalic  Acid,  Hydrate  of  Potassa,  Ammonia, 
Carbonate  of  Ammonia,  Chloride  of  Ammonium,  Molybdate  of  Ammo- 
nia, Ferrocyanide  of  Potassium,  Ferridcyanide  of  Potassium,  Bichloride 
of  Platinum,  Acetate  of  Lead,  Sulphuretted  Hydrogen  Water,  Sulphy- 
drate  of  Ammonia,  Alcohol,  Distilled  Water. 

The  principal  auxiliary  apparatus  are  :  Test-tubes  and  Test-tube  Rack, 
small  Porcelain  Dishes,  small  Beaker  Glasses,  some  Glass  Funnels  and 
Filtering  Stand,  Filtering  Paper,  Platinum  Crucible,  some  Glass  Rods 
and  round  Glass  Plates,  for  covering  beaker  glasses,  a  common  Spirit 
Lamp,  and  a  Spirit  Lamp  with  Argand  Burner. 


SECOND  CHAPTER. 


GENERAL  ROUTINE  OF  BLOWPIPE  ANALYSIS. 

$  7.  ON  examining  a  substance  before  the  blowpipe,  with  a  view  to 
determine  its  nature  or  to  ascertain  the  presence  or  absence  of  certain 
matter,  it  is  advisable  to  follow  a  systematic  way,  composed  of  a  series 
of  operations,  and  to  attentively  observe  the  changes  which  the  body 
undergoes  under  the  influence  of  the  various  agents  which  are  brought 
to  act  upon  it.  The  various  operations  which  the  assay  is  submitted  to 
are  so  many  questions,  to  which  the  phenomena  which  we  observe  con- 
stitute so  many  answers  ;  and  from  their  appearance  or  non-appearance, 
we  are  able  to  draw  definite  conclusions  as  to  the  nature  of  the  substance 
under  examination. 

The  following  order,  and  the  rules  to  be  observed  in  the  execution  of 
the  various  operations  are,  essentially,  the  same  as  first  pointed  out  and 
laid  down  by  Berzelius. 

1.  Examination  in  a  glass  tube,  sealed  at  one  end,  or  a  matrass. 

2.  Examination  in  a  glass  tube  open  at  both  ends. 

3.  Examination  on  charcoal  per  se. 

4.  Examination  in  the  platinum-pointed  pincers,  or  on  platinum  wire 
per  se. 

5.  Examination  with  borax,  and  salt  of  phosphorus. 

6.  Examination  with  carbonate  of  soda. 

7.  Examination  with  solution  of  cobalt. 

2* 


18 


Regarding  the  size  of  the  assay,  a  piece  the  size  of  a  mustard  seed  will 
generally  be  found  sufficient;  larger  pieces,  without  showing  the  reaction 
more  distinctly,  requiring  so  much  more  labor.  In  some  cases,  however, 
it  is  advantageous  to  employ  a  greater  quantity,  ex.  gr.  in  reductions,  or 
in  heating  in  a  glass  tube  ;  for  the  larger  the  metallic  globule,  and  the 
greater  the  amount  of  the  sublimate  produced,  the  more  readily  can  its 
nature  be  ascertained. 


Examination  in  a  closed  Glass  Tube,  or  a  Matrass. 

\  8.  The  assay-piece  is  introduced  into  a  glass  tube,  sealed  at  one  end, 
or  into  a  small  matrass,  and  heat  applied  by  means  of  a  common  spirit 
lamp.  The  heat  must  at  first  be  very  low,  but  may  be  gradually  raised 
to  redness,  if  necessary.  By  this  treatment  we  learn  : 

$  9.  1.  Whether  the  substance  is  entirely  or  partly  volatile  or  not. 

Among  the  phenomena  to  be  observed,  the  following  are  deserving  of 
particular  attention : 

The  substance  gives  out  water,  which  partly  escapes  and  partly  con- 
denses in  the  colder  portion  of  the  tube.  This  points  to  the  presence  of 
a  salt  containing  water  of  crystallization  [No.  22],  or  to  the  presence  of 
a  hydrate,  or  to  such  salts  which  contain  water  mechanically  inclosed 
between  the  laminas  of  the  crystals  [No.  18] ;  in  this  case  the  body  usu- 
ally decrepitates.  The  drops  of  condensed  water  are  to  be  examined 
with  test-paper:  an  alkaline  reaction  denotes  the  presence  of  ammonia, 
an  acid  reaction  the  presence  of  some  volatile  acid,  as  sulphuric,  nitric, 
hydrochloric,  hydrofluoric  acid,  &c. 

§  10.  The  substance  gives  out  a  gas  or  vapor.  Those  of  most  usual 
occurrence  are : 

a.  Oxygen,  easily  recognized  by  rekindling  into  flame  a  match  which 
has  been  extinguished  so  as  to  leave  only  a  spark  at  the  extremity; 
points  to  the  presence  of  a  peroxide,  nitrate,  chlorate,  bromate  or  iodate 
[No.  20]. 

b.  Sulphurous  acid,  easily  recognized  by  its  peculiar  odor  and  action 


19 


on  blue  litmus  paper;    indicates  the  presence   of  a  sulphate   or  sul- 
phite [No.  22]. 

c.  Sulphuretted  hydrogen,  recognized  by  its  peculiar  odor ;  indicates 
the  presence  of  sulphides  containing  water. 

d.  Nitrous  acid  or  peroxide  of  nitrogen,  recognized  by  its  deep  orange 
red  color  and   acid  reaction;    indicates   the   presence  of  a   nitrite  or 
nitrate  [No.  23]. 

e.  Carbonic  acid,  recognized  by  causing  a  turbidity  in  a  drop  of  lime- 
water  suspended  from  a  watch-crystal  and  exposed  to  the  escaping  gas ; 
points  to  the  presence  of  a  carbonate. 

f.  Cyanogen,  recognized  by  its  peculiar  odor  and  by  burning  with  a 
crimson  flame ;  indicates  the  presence  of  a  cyanogen-compound. 

g.  Ammonia,  recognized  by  its  odor  and  alkaline  reaction ;  indicates 
the  presence  of  an  ammoniacal  salt  or  of  an  organic  nitrogenous  sub- 
stance ;  in  the  latter  case,  the  mass  usually  blackens,  and  evolves  at  the 
same  time  either  cyanogen  or  empyreumatic  oils  of  offensive  odor  [No.  3]. 

$11.  The  substance  yields  a  sublimate.  The  sublimate  is  either 
white  or  possessed  of  a  peculiar  color.  White  sublimates  are  formed  by 

a.  Many  salts  of  ammonia ;  on  removing  the  sublimate  from  the  tube, 
placing  it  on  a  watch-crystal,  adding  a  drop  of  hydrate  of  potassa,  and 
applying  heat,  ammonia  is  evolved  [No.  19]. 

6.  The  chlorides  of  mercury  j  the  subchloride  sublimes  without  pre- 
vious fusion ;  the  protochloride  fuses  first,  then  sublimes ;  the  sublimate 
is  yellow  while  hot,  but  becomes  white  on  cooling  [Nos.  39  and  40]. 

c.  Oxide  of  antimony;  it  fuses  first  to  a  yellow  liquid,  then  sublimes; 
the  sublimate  consists  of  lustrous  needle-shaped  crystals  [No.  24], 

d.  Arsenous  acid ;  the  sublimate  consists  of  octahedral  crystals  [No. 
25]. 

e.  Tellurous  acid ;  shows  a  reaction  similar  to  that  of  oxide  of  anti- 
mony, but  requires  a  much  higher  temperature  ;  the  sublimate  is  amor- 
phous. 

Sublimates  possessed  of  metallic  lustre,  so-called  metallic  mirrors,  are 
formed  by : 

a.  Metallic  arsenic  and  arsenides  containing  more  than  one  equivalent 


20 


of  arsenic  to  two  of  metal,  also,  some  sulpli-arsenides  [No.  77]  ;  cutting 
the  tube  below  the  sublimate,  and  exposing  the  mirror  to  gentle  heat  in 
the  flame  of  a  spirit-lamp,  the  peculiar  odor  of  arsenic  is  perceived. 

5.  Mercury,  amalgams,  and  some  salts  of  mercury ;  the  sublimate  con- 
sists of  minute  globules  of  metallic  mercury,  which,  by  friction  with  a 
piece  of  copper  wire,  readily  unite  to  larger  globules  [No.  47]. 

c.  Some  alloys  of  cadmium. 

d.  Tellurium ;  only  at  a  very  high  temperature ;  the  sublimate  con- 
sists of  small  globules,  which  solidify  on  cooling. 

Sublimates  possessed  of  distinct  color  are  formed  by: 

a.  Sulphur  and  sulphides  containing  a  large  amount  of  sulphur;  the 
sublimate  is  from  deep-yellow  to  brownish-red  while  hot,  but  pure  sul- 
phur-yellow when  cold  [No.  75]. 

b.  The  sulphides  of  antimony,  alone  or  in  combination  with  other  sul- 
phides ;  the  sublimate  forms  only  at  a  very  high  temperature,  and  is  de- 
posited at  a  short  distance  from  the  assay-piece ;  it  is  black  while  hot, 
reddish-brown  when  cold  [No.  74]. 

c.  The  sulphides  of  arsenic  and  some  compounds  of  metallic  sulphides 
with  arsenides ;  the  sublimate  is  dark  brownish-red  while  hot,  but  from 
reddish-yellow  to  red  when  cold  [No.  80]. 

d.  Cinnabar ;  the  sublimate  is  black,  without  lustre,  and  yields  a  red 
powder  on  being  scratched  with  a  knife  [No.  81 J. 

e.  Selenium  and  some  selenides ;  the  sublimate  appears  only  at  a  high 
temperature,  is  of  a  reddish  or  black  color,  and  yields  a  dark-red  powder; 
at  the  open  end  of  the  tube  the  peculiar  odor  of  selenium  (resembling- 
rotten  horse-radish)  is  perceived  [No.  87]. 

\  12.  2.  Whether  the  substance  undergoes  any  change,  or  remains 
unaltered. 

Many  substances,  under  this  treatment,  suffer  physical  changes  with- 
out being  affected  in  their  chemical  constitution.  A  great  many  miner- 
als, when  heated,  decrepitate ;  others  phosphoresce,  as  fluor-spar  and 
apatite.  The  most  important  of  these  physical  changes,  is  that  of  color: 
from  white  to  yellow,  and  white  again  on  cooling,  points  to  oxide  of 
zinc  [No.  36]  ;  from  white  to  yellowish-brown,  dirty  pale-yellow  on  cool- 


ing,  points  to  oxide  of  tin  [No.  33];  from  white  to  brownish-red,  yellow 
when  cold,  and  fusible  at  a  red  heat,  points  to  oxide  of  lead  [No.  72] ; 
from  white  to  orange-yellow  or  reddish-brown,  pale-yellow  when  cold,  and 
fusible  at  a  bright  red  heat,  points  to  teroxide  of  bismuth ;  from  red  to 
black,  and  red  again  on  cooling,  points  to  sesquioxide  of  iron  [No.  64]. 


Examination  in  a  Glass  Tube  open  at  both  ends. 

$  13.  The  assay-piece  is  introduced  into  the  tube  to  a  depth  of  about 
half  an  inch,  the  end  to  which  it  lies  nearest  slightly  inclined,  and  heat 
applied.  The  air  contained  in  the  tube  becomes  heated;  it  rises, 
escapes  from  the  upper  end,  and  fresh  air  enters  from  below.  In  this 
manner  a  calcination  is  effected,  and  many  substances  which  remained 
unchanged  when  heated  in  a  matrass,  yield  sublimates  or  gaseous  pro- 
ducts when  subjected  to  this  treatment,  owing  to  the  formation  of  vola- 
tile oxides. 

By  this  means  we  can  easily  detect  the  presence  of  the  following  sub- 
stances : 

$14.  Sulphur;  sulphurous  acid  is  formed,  which  is  characterized  by 
its  peculiar  odor  and  action  on  moistened  litmus  paper  [No.  75] . 

$  15.  Arsenic;  if  present  in  sufficient  quantity  it  yields  a  white  and 
very  volatile  sublimate  of  arsenous  acid,  consisting  of  minute  octahedral 
crystals;  by  application  of  gentle  heat  it  may  be  driven  from  one  place 
to  another  [No.  77]. 

$ 16.  Antimony;  white  fumes  of  antimonous  acid  are  given  out  which 
partly  escape,  and  partly  condense  in  the  upper  part  of  the  tube.  The 
sublimate  is  a  white  powder,  and  may,  if  consisting  of  pure  antimo- 
nous acid,  be  volatilized  by  heat.  In  most  cases,  however,  the  oxidation 
proceeds  farther,  and  the  antimonate  of  the  oxide  of  antimony,  a  non- 
volatile white  powder,  is  formed  [No.  41]. 

§  17.  Metallic  Bismuth  ;  it  is  converted  into  oxide,  which  condenses  at 
a  short  distance  from  the  assay,  and  which,  by  heat,  may  be  fused  to 
brownish  globules  [No.  43]. 


Mercury  and  amalgams ;  yield  sublimates  of  metallic  mercury  [No. 
47]. 

$  18.  Tellurium  and  tellurides;  tellurous  acid  is  produced,  which  con- 
denses in  the  upper  part  of  the  tube  to  a  white  non-volatile  powder ;  on 
application  of  heat  it  fuses  to  colorless  globules. 

Selenium  and  selenides  ;  evolve  a  gaseous  oxide  of  a  peculiar  odor, 
resembling  that  of  rotten  horse-radish  [No.  87]. 


Examination  on  Charcoal  per  se. 

$  19.  In  examinations  of  this  kind,  particular  attention  must  be  paid 
to  the  odor  of  the  escaping  gases,  and  to  the  color  and  other  properties 
of  the  rings,  or  coatings,  which  form  on  the  charcoal  around  the  assay- 
piece.  The  interior  [reduction  flame,  R  Fl]  and  exterior  [oxidation 
flame,  0  Fl]  cones  of  the  flame  acting  in  an  opposite  sense,  the  phe- 
nomena produced  will  be  very  different ;  hence,  two  assays  should  always 
be  made,  exposing  the  substance  first  to  the  action  of  the  0  Fl  and  then 
to  the  action  of  the  R  Fl.  The  following  bodies  undergo,  when  submit- 
ted to  this  treatment,  characteristic  changes. 

$  20.  Arsenic :  It  is  volatilized  without  previous  fusion,  the  Ch  is 
covered  with  a  white  Ct,  which  is  far  distant  from  the  assay-piece,  and 
which  is  produced  by  both  the  0  Fl  and  R  Fl ;  the  Ct  is  very  volatile, 
and  is  easily  driven  away  by  the  Blp  flame,  emitting  the  peculiar  allia- 
ceous odor  characteristic  of  arsenic  [No.  42]. 

$  21.  Antimony:  It  enters  readily  into  fusion  and  covers  the  Ch  with 
white  oxide ;  the  ring  is  not  so  far  distant  from  the  assay-piece  as  in  the 
case  of  arsenic ;  it  may  be  driven  away  by  the  Blp  flame,  but  is  not  so 
volatile  as  that  of  arsenic,  and  does  not  emit  an  alliaceous  odor.  Metal- 
lic antimony,  when  fused  on  Ch  and  heated  to  redness,  remains  a 
considerable  time  in  a  state  of  ignition  without  the  aid  of  the  Blp,  dis- 
engaging, at  the  same  time,  a  thick  white  smoke,  which  is  partly  depo- 
sited on  the  Ch  around  the  metallic  globule  in  white  crystals  of  a  pearly 
lustre  [No.  41]. 


23 


$  22.  Bismuth  :  It  fuses  readily  in  both  flames  and  covers  the  Ch  with 
oxide,  which  is  dark  orange-yellow  while  hot  and  lemon-yellow  when 
cold.  The  yellow  Ct  is  usually  surrounded  by  a  white  ring,  consisting 
of  carbonate  of  bismuth.  The  Ct  is  somewhat  nearer  the  assay  than 
that  of  antimony;  it  may  be  driven  away  by  both  flames;  but  the  oxide 
of  antimony,  when  played  upon  with  the  R  Fl,  imparts  to  the  flame  a 
greenish-blue  tinge,  which  the  oxide  of  bismuth  does  not  [No.  43]. 

$  23.  Lead  :  It  fuses  easily  and  coats  the  Ch  in  both  flames  with  oxide, 
which  is  dark  lemon-yellow  while  hot  and  sulphur-yellow  when  cold;  in 
thin  layers  it  is  bluish-white  and  consists  of  carbonate.  The  Ct  is  found 
at  the  same  distance  from  the  assay  as  that  of  bismuth  ;  it  may  be  driven 
away  by  both  flames  ;  when  played  upon  with  the  R  Fl  it  imparts  to  the 
flame  an  azure-blue  color  [No.  11]. 

|  24.  Cadmium :  It  fuses  readily ;  exposed  to  the  0  Fl  it  burns  with 
a  dark-yellow  flame,  emitting  brown  fumes  of  oxide  which  cover  the  Ch 
around  the  assay.  This  Ct  is  very  characteristic ;  it  is,  when  cold,  of  a 
reddish-brown  color,  in  thin  layers  orange-yellow ;  it  is  easily  volatilized 
by  both  flames,  without  imparting  a  color  to  them  [No.  44]. 

§  25.  Zinc:  It  fuses  readily;  exposed  to  the  0  Fl  it  burns  with  an  in- 
tensely luminous  greenish-white  flame,  emitting  at  the  same  time  a  thick 
white  smoke  which,  partly  condensing  on  the  Ch,  covers  it  with  oxide, 
yellow  while  hot  and  white  when  cold.  The  Ct  when  played  upon  with 
the  0  Fl  becomes  luminous,  but  does  not  disappear  [No.  46]. 

$  26.  Tin  :  It  fuses  readily ;  exposed  to  the  0  Fl  it  is  converted  into 
oxide,  which  may  be  blown  away  and  thus  be  made  to  appear  as  a  Ct; 
it  is  always  found  closely  surrounding  the  assay-piece,  is  slightly  yellow 
and  luminous  while  hot,  white  when  cold,  and  non- volatile  in  both 
flames.  Exposed  to  the  R  Fl  the  molten  metal  retains  its  bright  metal- 
lic aspect  [No.  13]. 

§  27.  Silver:  When  exposed  for  a  long  time  to  the  action  of  the  R  Fl 
it  yields  a  slight  dark-red  Ct  of  oxide  [No.  45]. 

§  28.  Selenium :  It  fuses  very  readily  in  both  flames  with  disengage- 
ment of  brown  fumes ;  at  a  short  distance  from  the  "assay  a  steel-gray  Ct 
of  a  feeble  metallic  lustre  is  deposited  ;  played  upon  with  the  R  Fl  it  dis- 


24 


appears  with  emission  of  a  strong  odor  of  rotten  horse-radish,  at  the  same 
time  imparting  to  the  flame  a  fine  blue  color  [No.  87]. 

§  29.  Tellurium :  It  fuses  very  readily  and  coats  the  Ch  in  both 
flames  with  tellurous  acid ;  the  Ct  is  not  very  far  distant  from  the  assay  ; 
it  is  of  a  white  color  with  a  red  or  dark-yellow  edge  5  played  upon  with 
the  R  Fl  it  disappears,  imparting  to  the  flame  a  green  tinge. 

$  30.  Besides  the  above  named  metals  there  are  some  other  substances 
which,  when  treated  before  the  Blp  upon  Ch  cover  it  with  coatings, 
which  may  be  driven  away  when  played  upon  with  the  0  Fl,  and  which 
show  in  many  cases  a  great  resemblance  to  the  Ct  produced  by  anti- 
mony. Among  the  bodies  possessing  this  property  the  following  are  the 
most  frequently  occurring  ones  : 

The  sulphurides  of  potassium,  sodium,  and  lithium. 

The  chlorides  of  ammonium,  potassium,  sodium,  and  lithium. 

The  chlorides  of  mercury,  antimony,  zinc,  cadmium,  lead,  bismuth, 
tin,  and  copper. 

The  bromides  and  iodides  of  potassium  and  sodium. 


Examination  in  the  Platinum-pointed  Pincers. 

$  31.  This  experiment  serves  a  double  purpose.  It  acquaints  us  with 
the  degree  of  fusibility  of  the  assay,  and  shows  the  presence  or  absence 
of  such  substances  which  possess  the  property  of  imparting  to  the  flame 
a  peculiar  color.  Many  metals,  the  sulphurides,  and  some  other  com- 
pounds act  upon  metallic  platinum  at  a  high  temperature  ;  the  fusi- 
bility, «fec.,  of  such  substances  ought  to  be  tested  on  Ch.  Others,  again, 
fuse  so  easily  that  they  cannot  be  held  a  sufficiently  long  time  between 
the  pincers  to  observe  the  color  which  they  impart  to  the  flame;  they 
are  most  conveniently  attached  to  the  hook  of  the  platinum  wire,  which 
is  best  done  by  heating  the  wire  to  redness  and  then  touching  the  powder 
of  the  assay  with  it ;  a  sufficient  quantity  generally  remains  adhering  to 
the  wire. 

Some  minerals  decrepitate  violently  as  soon  as  they  are  touched  with 


the  flame ;  in  such  cases,  Berzelius  advises  to  powder  the  substance  very 
finely  in  an  agate-mortar  with  addition  of  a  little  water,  to  place  one  or 
two  drops  of  the  mixture  on  a  piece  of  Ch,  and  to  gently  heat  it  by 
means  of  the  Blp  flame  until  the  mass  lies  loosely  upon  the  Ch ;  it  may 
then  be  taken  up  and  held  by  the  pincers.  The  same  process  is  ad- 
vantageously employed  with  substances  which  fuse  only  at  a  very  high 
temperature.  In  all  other  cases  the  substance  is  roughly  powdered  and 
a  thin  piece  which  shows  prominent  edges  selected  for  the  experiment. 

The  assay  is  exposed  to  the  action  of  the  inner  cone  of  the  flame, 
when  the  outer  cone  may  exhibit  the  following  changes  of  color : 

I  32.  1.  Yellow. 

Soda  and  its  salts  cause  an  enlargement  of  the  outer  flame,  and  im- 
part, at  the  same  time,  an  intense  reddish-yellow  color  [No.  18].  The 
presence  of  other  substances  which  also  possess  the  property  of  coloring 
the  flame,  but  not  in  so  high  a  degree,  does  not  prevent  the  reaction. 
Silicates  containing  soda,  exhibit  the  same  phenomenon  to  a  smaller  or 
greater  extent,  according  to  their  degree  of  fusibility  and  the  amount  of 
soda  which  they  contain  [No.  62].  With  many  salts  of  soda,  which  do 
not  exhibit  the  reaction  very  distinctly,  it  can  be  produced  by  mixing 
the  salt  with  some  chloride  of  silver  to  a  paste  (v.  g  5),  fastening  it  to 
the  hook  of  a  thin  iron-wire,  and  then  exposing  it  to  the  action  of  the 
inner  name.  * 

g  33.  2.  Violet. 

Potassa  and  many  of  its  salts  impart  to  the  outer  flame  a  distinct 
violet  color  [No.  15].  The  presence  of  a  small  quantity  of  a  salt  of  soda 
or  lithia  prevents  the  reaction.  An  addition  of  chloride  of  silver  favors 
the  reaction  with  the  carbonate,  nitrate,  and  some  other  salts  of  potassa. 

I  34.  3.  Red. 

Lithia  and  its  salts  impart  to  the  outer  flame  a  fine  carmine-red  color 
[No.  63]  ;  the  chloride  of  lithium  shows  the  reaction  better  than  any 
other  salt.  The  presence  of  a  salt  of  potassa  does  not  prevent  the  reac- 
tion ;  the  presence  of  even  a  small  quantity  of  a  salt  of  soda  changes  the 
color  to  yellowish-red.  An  addition  of  chloride  of  silver  favors  the 
reaction  with  many  salts  of  lithia. 


26 


Chloride  of  strontium  and  some  other  salts  of  strontia,  ex.  gr.  the 
carbonate  and  the  sulphate,  color  the  outer  flame,  immediately  or  after  a 
while,  carmine-red  [No.  57].  The  presence  of  baryta  prevents  the  reac- 
tion. The  carbonate  and  sulphate  of  strontia  show  the  reaction  remark- 
ably well  when  mixed  with  chloride  of  silver  and  heated  on  iron-wire 
(v.  §  5). 

Chloride  of  calcium,  calcareous  spar,  many  compact  limestones,  and 
fluor-spar,  color  the  outer  flame,  immediately  or  after  a  while,  red ;  the 
color  is  not  so  intense  as  that  produced  by  strontia.  Gypsum  and  anhy- 
drite impart  at  first  a  pale  yellow,  afterwards  a  red  color  of  little  in- 
tensity [No.  56].  An  addition  of  chloride  of  silver  usually  increases  the 
intensity  of  the  color. 

|  35.  4.  Green. 

Chloride  of  barium,  carbonate  and  sulphate  of  baryta,  color  the  outer 
flame  yellowish-green.  The  presence  of  lime  does  not  prevent  the  reac- 
tion [No.  58].  An  addition  of  chloride  of  silver  makes  the  color  much 
more  intense. 

Oxide  of  copper  and  some  of  its  salts,  ex.  gr.  the  carbonate,  sulphate, 
and  nitrate,  impart  to  the  outer  flame  a  fine  emerald-green  color. 
Iodide  of  copper  and  some  silicates  containing  copper,  ex.  gr.  dioptase 
and  chrysocolla,  act  in  the  same  manner  [No.  73].  An  addition  of 
chloride  of  silver  produces  increased  intensity  of  color. 

Phosphoric  acid,  phosphates,  and  minerals  containing  phosphoric  acid, 
impart  to  the  outer  flame  a  bluish-green  color  [No.  3]. 

Boracic  acid  colors  the  outer  flame  yellowish  green  (greenfinch  color) 
[No.  5]  ;  if  a  small  quantity  of  soda  is  present  the  color  is  mixed  with 
yellow. 

Molybdic  acid,  oxide  of  molybdenum,  and  the  native  sulphide  of 
molybdenum,  color  the  outer  flame  yellowish-green,  like  baryta  [No.  83]. 

Tellurous  acid  enters  into  fusion,  emits  white  fumes,  and  colors  the 
outer  flame  green. 

\  36.  5.  Blue. 

Arsenic  and  some  arsenides,  ex.  gr.  smaltine  and  copper-nickel  [No. 
82]  when  heated  on  Ch  impart  a  light-blue  color  to  the  outer  flame. 


27 


Some  arsenates,  ex.  gr.  scorodite  and  cobalt  bloom,  exhibit  the  same 
phenomenon  in  the  pincers. 

Antimony,  fused  on  Ch  in  R  Fl  is  surrounded  by  a  very  feeble  bluish 
light.  [No.  41]. 

Metallic  lead,  fused  on  Ch  in  R  Fl  is  surrounded  by  an  azure-blue  light. 
Many  salts  of  lead,  heated  in  the  pincers  or  on  platinum  wire,  impart  an 
intense  azure-blue  color  to  the  outer  flame  [No.  11]. 

Chloride  of  copper  colors  the  outer  flame  intensely  azure-blue;  after  a 
while  the  color  becomes  green,  owing  to  the  formation  of  oxide  of  copper 
[No.  37]. 

Bromide  of  copper  colors  the  outer  flame  greenish-blue;  after  a  while 
the  color  changes  to  green. 

Selenium,  fused  on  Ch  in  R  Fl  vaporizes  with  an  azure-blue  light. 


Examination  with  Borax  and  Salt  of  Phosphorus. 

$  37.  The  examination  of  the  assay  with  borax  and  salt  of  phosphorus 
is  eminently  adapted  to  detect  the  presence  of  metallic  oxides,  a  great 
number  of  them  possessing  the  property  of  being  at  a  high  temperature 
dissolved  by  these  fluxes  with  a  peculiar  color.  Unoxidized  metals  and 
metallic  sulphides,  arsenides,  &c.,  differ  in  this  respect  very  materially 
from  the  pure  oxides  ;  hence  it  is  necessary,  before  performing  the  ex- 
periment, to  convert  all  such  substances  into  oxides.  This  is  effected 
by  calcination,  on  Ch  or  in  an  open  glass  tube.  The  finely  powdered 
assay  is  placed  on  Ch  and  alternately  treated  with  the  0  Fl  and  R  Fl, 
and  this  process  is  repeated  until  the  substance  no  longer  emits,  while  in 
the  incandescent  state,  the  odor  of  sulphur  or  arsenic.  The  heat  must 
never  be  raised  so  high  as  to  cause  fusion,  and  between  every  two  suc- 
ceeding calcinations  the  assay  should  be  taken  from  the  Ch  and  freshly 
powdered. 

The  experiment  is  generally  made  on  platinum  wire,  where  the  color  of 
the  bead  is  more  readily  observed;  Ch  is  used  only  in  such  cases  where 
the  substance  under  examination  contains  metallic  oxides  which  are 


easily  reduced.  It  is  not  sufficient  to  observe  the  color  of  the  bead  after 
cooling  |  but  all  changes  of  color  which  take  place  during  the  action  of 
the  flame,  and  through  all  the  various  stages  of  cooling,  should  be  care- 
fully noticed. 

Some  substances  possess  the  property  of  forming  a  limpid  glass  with 
borax,  which  preserves  its  transparency  on  cooling,  but  which,  if  slightly 
heated  in  the  0  Fl  becomes  opaque,  when  the  flame  strikes  it  in  an  une- 
qual or  intermittent  manner.  This  operation  has  received  the  name  of 
"  flaming,"  and  any  substance  thus  acted  upon  is  said  to  become  "opaque 
by  flaming." 

The  third  and  fourth  columns  of  Tables  I  and  II  exhibit  the  behavior 
of  the  most  important  oxides  to  borax  and  salt  of  phosphorus. 

In  Table  III  the  oxides  are  arranged  with  reference  to  the  color  which 
they  impart  to  the  beads  in  0  Fl  and  R  Fl. 


Examination  ivitJi  Carbonate  of  Soda. 

$  38.  In  subjecting  a  body  to  the  treatment  with  Sd  we  have  to  direct 
our  attention  to  two  points. 

Some  substances  unite  with  Sd  to  fusible  compounds,  others  form  in- 
fusible compounds,  and  others  again  are  not  acted  upon  at  all ;  in  the 
last  case  the  Sd  is  absorbed  by  the  Ch  and  the  assay  is  left  unchanged. 
With  Sd  unite  to  fusible  compounds  with  effervescence : 

$  39.  Silicic  acid ;  it  fuses  to  a  transparent  glassy  bead  which,  after 
cooling,  remains  transparent  if  the  Sd  has  not  been  added  in  excess 
[No.  54]. 

Titanic  acid ;  it  fuses  to  a  transparent  glassy  bead  which,  when  cold, 
is  opaque  and  of  crystalline  structure  [No.  65]. 

Tungstic  and  molybdic  acids ;  the  mass,  after  the  union  has  been 
effected,  is  absorbed  by  the  Ch  [No.  31  and  No.  34]. 

The  salts  of  baryta  and  strontia  form  with  Sd  fusible  compounds  which 
are  absorbed  by  the  Ch  [No.  57  and  No.  58]. 

g  40.  The  second  point  to  be  observed  is  the  elimination  of  metallic 


matter.  Of  the  metallic  oxides,  when  treated  with  Sd  on  Ch  in  R  Fl, 
are  reduced  :  the  oxides  of  the  noble  metals  and  the  oxides  of  arsenic, 
antimony,  bismuth,  cadmium,  copper,  cobalt,  iron,  lead,  mercury,  nickel, 
tin,  zinc,  molybdenum,  tungsten,  and  tellurium.  Of  these,  arsenic  and 
mercury  vaporize  so  rapidly  that  frequently  not  even  a  coating  is  left  on 
the  Ch.  Antimony,  bismuth,  cadmium,  lead,  zinc,  and  tellurium  are 
partly  volatilized  and  form  distinct  coatings  on  the  Ch.  The  non-volatile 
reduced  metals  are  found  mixed  up  with  the  Sd.  To  separate  them 
from  the  adhering  Sd  and  Ch  powder,  we  may  proceed  in  the  following 
manner : 

The  fused  mass  of  Sd  and  metal,  and  the  portion  of  the  Ch  immedi- 
ately below  and  around  the  assay,  is  placed  in  the  little  agate  mortar, 
rubbed  to  powder,  the  powder  mixed  with  a  little  water,  and  stirred  up. 
The  heavy  metallic  particles  settle  to  the  bottom,  part  of  the  Sd  dis- 
solves, and  the  Ch  powder  remains  suspended  in  the  water.  The  liquid 
is  carefully  poured  off,  and  the  residue  treated  repeatedly  in  the  same 
manner  until  all  foreign  matter  is  removed.  The  metal  remains  behind 
as  a  dark  heavy  powder  or,  when  the  metal  is  ductile  and  easily  fusible, 
in  the  shape  of  small  flattened  scales  of  metallic  lustre.  If  the  substance 
under  examination  contained  several  metallic  oxides,  the  metallic  mass 
obtained  is  usually  an  alloy,  in  which  the  several  metals  may  be  recog- 
nized by  processes  to  be  described  hereafter.  It  is  only  in  some  excep- 
tional cases  that  separate  metallic  globules  are  obtained,  ex.  gr.  in 
substances  containing  iron  and  copper. 

For  a  more  detailed  account  of  the  behavior  of  the  various  metallic 
oxides  under  this  treatment,  see  the  second  column  of  Tables  I  and  II. 

|  41.  The  examination  with  Sd  is  usually  performed  on  Ch  in  the 
R  Fl,  and,  as  a  general  rule,  the  flux  is  added  successively  in  small  por- 
tions. This  is  particularly  necessary  when  the  assay  is  to  be  tested  for 
its  fusibility  with  Sd,  since  a  great  many  minerals,  &c.,  behave  very 
differently  with  different  quantities  of  the  flux. 

§  42.  Instead  of  carbonate  of  soda,  the  neutral  oxalate  of  potassa  or 
cyanide  of  potassium  may  be  advantageously  used  for  all  experiments  of 
reduction,  since  these  reagents  exercise  a  more  powerful  reducing  action 


30 


than  common  Sd.  They  are,  for  this  reason,  frequently  employed  when 
the  presence  of  such  metallic  oxides  is  suspected,  whose  conversion  into 
metals  require  high  temperatures  and  the  aid  of  a  very  efficient  deoxi- 
dizing agent. 

Examination  with  Solution  of  Cobalt. 

%  43.  A  few  substances,  when  moistened  with  a  solution  of  nitrate  of 
cobalt  and  exposed  to  the  action  of  the  0  Fl,  assume  a  peculiar  color. 
The  use  of  this  test  is,  however,  very  limited,  since  the  reaction  can  only 
clearly  be  seen  in  such  bodies  which,  after  having  been  acted  upon  by 
the  0  Fl,  present  a  white  appearance,  or  nearly  so. 

$  44.  Substances  which  are  sufficiently  porous  to  imbue  a  liquid,  are 
merely  moistened  with  a  drop  of  S  Co,  placed  into  the  platinum-pointed 
pincers,  and  treated  with  the  0  Fl.  Other  substances  must  be  powdered, 
the  powder  placed  on  Ch,  wetted  with  a  drop  of  S  Co,  and  treated  as 
above.  The  color  can  only  be  distinguished  after  cooling.  A  bluish 
color,  of  more  or  less  purity,  indicates  the  presence  of  alumina  [No.  21]  ; 
and  a  pale-reddish  color  [flesh-color]  that  of  magnesia  [No.  59.]  It 
must,  however,  be  borne  in  mind,  that  the  alkaline  and  some  other 
silicates,  when  heated  with  S  Co  to  a  temperature  above  their  fusing 
point,  also  assume  a  blue  color,  owing  to  the  formation  of  silicate  of  co- 
balt. In  testing  for  alumina,  therefore,  the  heat  must  not  be  raised  so 
high  as  to  cause  fusion  of  the  assay.  In  testing  for  magnesia  this  pre- 
caution is  not  necessary ;  on  the  contrary,  the  color  will  appear  the 
brighter  and  the  more  distinct,  the  higher  the  temperature  to  which  the 
assay  was  exposed. 

$45.  Among  the  oxides  of  the  heavy  metals,  those  of  zinc  and  tin 
assume  characteristic  colors  with  S  Co.  The  reaction  is  best  seen  when 
the  assay,  alone  or  mixed  with  Sd,  is  exposed  to  the  R  Fl  on  Ch.  The 
ring  of  oxide  which  is  deposited  around  the  assay  is  then  moistened  with 
S  Co  and  treated  with  the  0  Fl.  Oxide  of  zinc  takes  a  fine  yellowish- 
green,  and  oxide  of  tin  a  bluish-green  color  [No.  36  &  No.  33]. 

g  46.  Besides  the  compounds  above  mentioned  there  are  some  others 


31 


which,  when  exposed  to  the  action  of  S  Co  and  0  Fl,  experience  a  change 
of  color.  These  bodies  are  either  of  very  rare  occurrence,  or  the  change 
produced  in  them  is  not  sufficiently  distinct.  It  will,  therefore,  be  suffi- 
cient merely  to  mention  the  names  of  the  compounds  and  the  color  which 
S  Co  imparts  to  them: 

Baryta  [brownish-red],  tantalic  acid  [flesh-color],  zirconia  and  phos- 
phate of  magnesia  [violet],  titanic  acid,  niobic  acid,  and  antimonic  acid 
[green],  strontia,  lime,  glucina,  and  pelopic  acid  [gray]. 


THIRD  CHAPTER. 



SPECIAL  REACTIONS  FOR  THE  DETECTION  OF  CERTAIN 
SUBSTANCES  WHEN  IN  COMBINATION  WITH  OTHERS. 

\  47.  THE  preceding  chapter  and  accompanying  tables  show  the 
changes  which  many  of  the  simple  chemical  compounds  undergo  when 
heated,  or  when  treated  with  the  usual  blowpipe  reagents.  The  reac- 
tions are  sufficiently  characteristic  to  distinguish  the  various  compounds 
from  each  other,  so  that,  when  any  of  the  above  named  substances  in  a 
pure  state  is  under  examination,  there  is  no  difficulty  to  determine  its 
nature.  This,  however,  is  not  of  frequent  occurrence,  and  in  the  majority 
of  cases  the  body  to  be  tested  will  be  of  a  more  complex  nature.  The 
results  of  the  experiments  will  vary  accordingly.  For  instance,  an  ore  of 
cobalt,  containing  iron,  will  not  impart  to  the  bead  of  Bx  or  S  Ph  in  the 
0  Fl  a  blue  color,  but  a  green  one,  resulting  from  the  mixture  of  the 
blue  of  cobalt  and  the  yellow  of  iron;  lead,  when  accompanied  by  anti- 
mony, deposits  a  dark-yellow  coating  on  Ch  resembling  that  of  bismuth, 
&c.  In  such  cases  we  may  often,  by  attentively  observing  all  the  phe- 
nomena which  present  themselves,  and  by  carefully  comparing  the  results 
obtained  by  the  various  experiments,  detect  many,  if  not  all,  of  the  com- 
ponents of  the  substance  under  examination.  Sometimes  we  attain  this 
end  quicker  by  varying  the  order,  or  by  introducing  auxiliary  agents  into 
the  series  of  experiments  ;  and  in  other  cases,  again,  it  is  only  to  be  ar- 
rived at  by  subjecting  the  assay  to  treatments  different  from  those  men- 
tioned in  the  preceding  pages. 

This  chapter  contains  the  principal  reactions  for  the  detection  of  sub- 


33 


stances  which  require  the  application  of  peculiar  agents,  and  the  methods 
for  ascertaining  the  presence  of  certain  bodies  when  in  combination  with 
others.  The  alphabetical  arrangement  will  be  found  of  practical  use. 

Ammonia. 

§  48.  Small  quantities  of  ammonia  are  best  detected  by  mixing  the 
powdered  assay  [No.  19]  with  some  carbonate  of  soda  or  caustic  potassa, 
introducing  the  mixture  into  a  glass  tube,  sealed  at  one  end,  and  applying 
heat.  The  escaping  gas  is  characterized  by  its  odor,  and  by  its  action  on 
reddened  litmus  paper.  From  the  appearance  of  this  reaction  we  are, 
however,  not  authorized  to  infer  the  pre-existence  of  ammonia  in  the 
assay,  since  from  organic  matter  containing  nitrogen,  when  subjected  to 
this  treatment,  ammonia  is  evolved  as  a  product  of  decomposition. 

Antimony. 

The  reactions  of  antimony  and  its  compounds,  see  g  11,  §  16,  |  21,  §  36, 
and  Table  II,  1. 

$ 49.  In  presence  of  lead  or  bismuth,  antimony  can  not  be  detected  by 
its  Ct  on  Ch.  In  this  case  the  metallic  compound  [No.  4-8,  or  No.  85]  is 
treated  with  vitrified  boracic  acid  on  Ch,  the  flame  being  so  directed  that 
the  glass  is  always  kept  covered  with  the  blue  cone,  the  metallic  globule 
being  on  the  side ;  by  this  means  the  metals  become  oxidized,  the  oxides 
of  lead  and  bismuth  are  absorbed  by  the  boracic  acid,  and  the  antimo- 
nous  acid  will  form  a  ring  on  the  Ch,  provided  the  temperature  was  not 
raised  too  high. 

$  50.  When  combined  with  metals  from  which  it  is  not  easily  sepa- 
rated, ex.  gr.  copper,  the  evaporation  of  the  antimony  takes  place  so 
slowly  that  no  distinct  Ct  is  produced.  In  this  case  the  assay  [No.  86] 
is  treated  with  S  Ph  on  Ch  in  the  0  Fl,  until  the  antimony,  or  at  least 
part  of  it,  has  become  oxidized  and  entered  into  the  flux.  The  glass  is 
now  removed  from  the  metallic  globule  and  treated  on  another  place  of 
the  Ch  with  metallic  tin  in  the  R  Fl ;  the  presence  of  antimony  will  cause 
the  glass  to  turn  gray  or  black  on  cooling  [Table  II,  1].  Bismuth  be- 
having under  these  circumstances  in  the  same  manner,  the  presence  of 
this  metal  makes  the  reaction  not  decisive  for  antimony.  The  humid 
way  has  then  to  be  resorted  to. 


34 


$51.  When  the  oxides  of  antimony  are  accompanied  by  such  metallic 
oxides  which,  when  reduced  on  Ch,  fuse  with  the  metallic  antimony  to 
an  alloy,  as  is  ex.  gr.  the  case  with  the  oxides  of  tin  and  copper,  the  latter 
cannot  be  recognized  by  a  simple  reduction.  The  oxides  have  to  be  treated 
with  a  mixture  of  Sd  and  Bx  on  Ch  in  the  R  Fl.  The  little  metallic 
globules  are  separated  from  the  flux,  and  fused  with  from  three  to  five 
times  their  own  volume  of  pure  lead  and  some  vitrified  boracic  acid  in 
the  R  Fl,  care  being  taken  to  play  with  the  flame  only  on  the  glass.  Anti- 
monous  acid  is  volatilized,  depositing  the  characteristic  ring,  while  the 
oxides  of  the  other  metals  are  absorbed  by  the  boracic  acid. 

$  52.  The  sulphides  of  antimony,  when  heated  in  the  open  glass  tube, 
show  the  reaction  mentioned  $  16.  When  accompanied  by  sulphide  of 
lead  [No.  89],  only  a  small  part  of  the  antimony  is  converted  into  anti- 
monous  acid,  which  sublimes ;  the  remainder  is  changed  into  a  white 
powder  consisting  of  a  mixture  of  antimonate  of  oxide  of  antimony,  sul- 
phate of  lead,  and  antimonate  of  lead.  When  a  compound  containing 
sulphide  of  lead  or  bismuth,  besides  sulphide  of  antimony,  is  heated  on 
Ch  in  the  R  Fl,  a  Ct  is  deposited  consisting  of  antimonous  acid  mixed 
with  sulphate  of  lead  or  bismuth  and,  nearer  to  the  assay,  a  yellow  one 
of  the  oxides  of  lead  or  bismuth ;  how  in  such  a  case  the  presence  of 
antimony  may  be  ascertained  v.  $  87. 

g  53.  To  detect  a  small  amount  of  sulphide  of  antimony  in  sulphide  of 
arsenic,  Plattner  strongly  recommends  the  following  method,  by  which 
he  obtained  very  decisive  and  satisfactory  results :  The  assay  [No.  88] 
is  introduced  into  a  glass  tube,  sealed  at  one  end,  and  gently  heated ;  the 
sulphide  of  arsenic  is  volatilized  and  the  greater  part  of  the  sulphide  of 
antimony  remains  as  a  black  powder  in  the  lower  end  of  the  tube ;  this 
end  is  cut  off,  the  black  substance  taken  out  and  transferred  to  a  tube 
open  at  both  ends.  By  applying  heat  the  characteristic  antimony-reac- 
tion will  appear. 

Arsenic. 

The  reactions  of  arsenic  and  its  compounds,  see  $  11,  $  15,  $  20,  $  34, 
and  Table  II,  2. 

§  54.  All  metallic  arsenides  yield  when  heated  in  the  open  glass  tube, 


35 


a  sublimate  of  arsenous  acid  (v.  $  15),  and  most  of  them  evolve  a  garlic 
odor  (v.  $  20)  when  heated  on  Ch  in  R  Fl  [No,  77].  Some  metals,  ex. 
gr.  nickel  and  cobalt,  have  a  great  affinity  for  arsenic,  so  that,  when  only 
a  small  quantity  of  the  latter  is  present,  the  characteristic  odor  is  not 
observable  5  in  such  cases  it  is  sometimes  produced  when  the  metallic 
compound  is  fused  on  Ch  with  some  pure  lead  in  the  0  Fl. 

$  55.  The  sulphides  of  arsenic,  heated  in  the  open  glass  tube,  evolve 
sulphurous  acid  and  yield  a  sublimate  of  arsenous  acid.  To  show  in  a 
very  decisive  manner  the  presence  of  arsenic  in  any  of  its  combinations 
with  sulphur,  the  powdered  assay  [No.  80]  is  mixed  with  six  parts  of  a 
mixture  of  equal  parts  of  cyanide  of  potassium  and  carbonate  of  soda, 
the  mass  introduced  into  a  tube  sealed  at  one  end,  and  heat  applied,  at 
first  very  gently  but  gradually  raised  to  redness.  A  ring  of  metallic 
arsenic  will  be  deposited  in  the  colder  part  of  the  tube. 

$  56.  When  sulph-arsenides  are  heated  on  Ch,  the  whole  of  the  arsenic, 
especially  when  only  small  quantities  are  present,  may  pass  off  in  combi- 
nation with  sulphur;  but  when  such  compounds  [No.  88]  are  mixed 
with  from  three  to  four  parts  of  cyanide  of  potassium  and  exposed  to  the 
R  Fl,  sulphide  of  potassium  is  formed  and  the  arsenic  escapes  with  its 
peculiar  odor. 

§  57.  To  detect  a  very  small  quantity  of  arsenous  acid,  the  following 
way  may  be  pursued:  a  glass  tube  provided  with  a  small  bulb  at  one  end 
is  close  above  it  narrowly  drawn  out;  the  assay  [No.  38]  is  introduced 
into  the  bulb,  and  a  charcoal  splinter  placed  into  the  tube  ;  the  narrow 
aperture  through  which  the  tube  communicates  with  the  bulb  prevents 
the  Ch  from  coming  in  contact  with  the  substance.  The  tube  is  then 
heated  to  redness  at  the  place  where  the  charcoal  splinter  lies,  and  as  soon 
as  this  is  incandescent,  heat  is  also  applied  to  the  bulb.  The  arseuous  acid 
is  volatilized  and  its  vapors,  while  passing  over  the  red  hot  charcoal, 
become  reduced  and  deposit  a  black  metallic  ring  of  arsenic  in  the  colder 
part  of  the  tube.  By  cutting  the  tube  below  the  ring  and  heating  this 
part  by  the  flame  of  a  spirit-lamp,  the  arsenic  is  volatilized,  thereby 
emitting  its  characteristic  odor. 

$  58.  To  show  the  presence  of  arsenic  in  arsenites  and  arsenates,  it 


will  in  most  cases  be  sufficient  to  mix  the  substance  [No.  38]  with  car- 
bonate of  soda  and  heat  it  on  Ch  in  R  Fl.  Sometimes  it  is  necessary  to 
treat  the  assay  with  a  mixture  of  carbonate  of  soda  and  cyanide  of  potas- 
sium in  the  manner  mentioned,  $  55  ;  and  in  other  cases  again,  where 
but  small  quantities  of  arsenous  or  arsenic  acid  are  combined  with 
metallic  oxides  which  are  readily  reduced,  recourse  must  be  had  to  the 
humid  way. 

Bismuth. 

The  reactions  of  bismuth  and  its  compounds,  see  \  12,  §  17,  §  22,  and 
Table  II,  3. 

$  59.  Bismuth  when  alloyed  with  other  metals,  or  when  as  sulphide  in 
combination  with  other  sulphides,  is  in  many  cases,  and  most  especially 
so  when  accompanied  by  lead  or  antimony,  not  to  be  detected  by  the 
ring  which  it  deposits  on  Ch.  In  such  a  case  the  assay  [No.  49]  is 
treated  on  Ch  until  a  copious  yellow  Ct  is  formed.  The  Ct  is  carefully 
scraped  off  from  the  Ch  and  dissolved  in  S  Ph  on  platinum  wire  with  the 
0  Fl.  The  colorless  bead  is  removed  from  the  wire,  placed  on  Ch,  a 
little  metallic  tin  added,  and  the  whole  exposed  to  the  R  Fl.  If  bismuth 
was  present,  the  glass  assumes,  on  cooling,  a  dark-gray  or  black  color. 
The  oxides  of  antimony  showing  the  same  behavior,  the  assay,  if  not 
quite  free  from  antimony,  has  to  be  treated  on  Ch  in  the  0  Fl  until  the 
whole  of  it  has  been  volatilized,  and  the  remaining  mass  treated  on 
another  piece  of  Ch  as  above  mentioned. 

Boracic  Acid. 

$  60.  With  many  borates,  which  do  not  impart  to  the  outer  flame  the 
peculiar  yellowish-green  color  [v.  $  35],  this  reaction  may  be  produced 
by  reducing  the  substance  [No.  2]  to  powder,  adding  a  drop  of  concen- 
trated sulphuric  acid,  fastening  the  mixture  into  the  hook  of  the  platinum 
wire,  and  playing  on  it  with  the  blue  cone  of  the  flame. 

§  61.  Another  way,  and  by  which  even  a  very  small  quantity  of  boracic 
acid  in  salts  and  minerals  may  be  detected,  is  :  to  reduce  the  substance 
to  a  very  fine  powder,  to  mix  it  with  from  3  to  4  parts  of  a  mixture  of  4  J 
parts  of  bisulphate  of  potassa  and  1  part  of  fluorspar,  and  to  knead  the 
whole  with  a  little  water  into  a  thick  paste.  This  mass  is  then  fastened 


37 


to  a  platinum  wire,  and  exposed  to  the  blue  cone  of  the  flame.  While 
the  mass  enters  into  fusion  fluoboric  acid  is  formed  which,  on  escaping, 
colors  the  flame  intensely  yellowish-green.  The  reaction  appearing  some- 
times only  for  a  few  seconds,  the  flame  should  be  very  attentively  watched 
during  the  whole  time  of  the  experiment. 
Bromine. 

%  02.  Bromides  treated  with  S  Ph  and  oxide  of  copper  on  platinum 
wire,  or  treated  with  sulphate  of  copper  on  silver  foil,  show  the  same  re- 
action as  chlorides  (v.  §  66),  with  this  difference,  that  the  blue  color  of 
the  outer  flame  is  rather  greenish,  especially  on  the  edges  [No.  16]. 

$  63.  To  discriminate  bromides  from  chlorides  more  distinctly,  the 
bromide  is  fused  with  bisulphate  of  potassa,  both  in  the  anhydrous  state, 
in  a  small  matrass  with  long  neck.  Sulphurous  acid  is  evolved,  and  the 
matrass  is  filled  with  yellow  vapors  of  bromine,  characterized  by  their 
peculiar  odor.  The  color  of  the  gas  is  only  clearly  seen  at  daylight. 

Cadmium. 

The  reactions  of  cadmium  and  its  compounds,  see  $§11,  24,  and 
Table  II,  4. 

$  64.  To  detect  a  very  small  quantity  of  cadmium,  one  per  cent,  or  less, 
in  zinc  or  its  ores,  the  pulverized  assay  is  mixed  with  Sdand  exposed  for 
a  short  time  to  the  RF1  on  Ch.  A  distinct  Ct  of  oxide  of  cadmium  is 
deposited.  The  zinc  being  less  volatile,  evaporates  only  with  continued 
blowing  [No.  53]. 

Chlorine. 

$  65.  Some  oxide  of  copper  is  dissolved  by  means  of  the  0  Fl  in  a  bead 
of  S  Ph  on  platinum  wire,  until  it  has  assumed  a  deep  green  color.  Some 
grains  of  the  pulverized  assay  [No.  18]  are  then  made  to  adhere  to  the 
bead,  and  both  heated  with  the  blue  cone  of  the  flame.  If  chlorine  is 
present  the  flame  now  assumes  an  intense  azure-blue  color,  owing  to  the 
formation  of  chloride  of  copper  (v.  \  36).  This  test  is  very  delicate,  and 
will  show  the  presence  of  a  very  minute  quantity  of  chlorine. 

$  66.  Another  method  is  to  place  on  silver-foil  some  protosulphate  of 
iron,  or  some  sulphate  of  copper,  to  moisten  it  with  a  drop  of  water,  and 
then  to  add  the  assay  [No.  18].  After  a  while  the  silver  will  be  found 

4 


blackened.  Substances  which  are  insoluble  in  water  have  previously  to 
be  fused  with  a  little  Sd  on  platinum  wire,  to  form  a  soluble  chloride 
[No.  10]. 

Chlorides,  when  moistened  with  sulphuric  acid  and  exposed  to  the  Blp 
flame,  impart  to  it  a  faint  green  coloration  which,  however,  is  generally 
confined  to  the  inner  cone,  and  is  quantitatively  of  much  less  intensity 
than  that  produced  with  borates.  A  small  amount  of  boracic  acid,  when 
occurring  together  with  a  chloride,  can,  therefore,  not  be  detected  by  the 
method  mentioned  $  60. 

Chromium. 

$  67.  Oxide  of  chromium  gives  very  characteristic  reactions  with  the 
fluxes  on  platinum  wire  (v.  Table  II,  6),  but  when  accompanied  by  a 
large  quantity  of  iron,  copper,  or  other  substances  which  also  intensely 
color  the  Bx  and  S  Ph  beads,  the  chromium  color  frequently  becomes 
very  indistinct. 

§  68.  In  such  a  case,  and  when  the  chromium  is  not  in  combination 
with  silicic  acid,  its  presence  may  be  detected  in  the  following  manner : 
The  assay-piece  [No.  71]  is  reduced  to  a  fine  powder  and  mixed  with 
about  four  times  its  own  volume  of  a  mixture  of  equal  parts  of  Sd  and 
nitre.  The  mass  is  fastened  into  the  hook  of  a  thick  platinum  wire,  or 
placed  into  a  small  platinum  spoon,  and  treated  with  a  powerful  0  Kl. 
An  alkaline  chromate  is  formed  which  is  dissolved  in  water,  the  solution 
supersaturated  with  acetic  acid,  and  a  crystal  of  acetate  of  lead  added. 
If  chromium  was  present,  a  yellow  precipitate  of  chromate  of  lead  will 
appear.  The  precipitate  may  be  collected  on  a  filter  and  tested  in  the  Bx 
and  S  Ph  beads,  when  the  characteristic  chromium-reactions  will  be  pro- 
duced. 
Cobalt. 

The  reactions  of  cobalt,  see  Table  II,  7. 

g  69.  To  detect  cobalt  when  in  combination  with  other  metals,  v.  \  83. 

To  show  its  presence  in  arsenides,  the  assay  [No.  78]  is  placed  on  Ch 
and  heated  until  no  longer  fumes  of  arsenous  acid  are  emitted.  (Lead 
and  bismuth,  if  present,  form  the  characteristic  coatings).  Bx  is  now 
added  and  the  heat  continued  until  the  glass  appears  colored.  If  the 


39 


color  is  not  pure  blue,  the  presence  of  iron  is  indicated.  The  glass  is  in 
this  case  removed  from  the  globule,  and  the  latter  treated  repeatedly  with 
fresh  quantities  of  Bx  until  the  pure  cobalt-color  is  obtained.  Nickel 
and  copper,  if  present,  do  not  enter  into  the  flux  before  the  whole  of  the 
cobalt  is  oxidized.  If  we  wish  to  ascertain  the  presence  of  these  metals, 
the  glass  which  is  colored  by  cobalt  is  removed  from  the  globule,  and  the 
latter  treated  with  fresh  portions  of  Bx  in  the  0  Fl  until  the  color  of  the 
bead  becomes  brown,  indicative  of  nickel.  The  glass  is  again  removed 
and  the  globule  treated  with  S  Ph  in  the  0  Fl ;  when  copper  is  present 
the  bead  assumes  a  green  color,  which  remains  unaltered  on  cooling. 
Treated  with  tin  on  Ch  the  glass  turns  opaque  and  red. 

$70.  To  detect  cobalt  in  sulphides,  the  assay  [No.  79]  is  heated  on 
Ch  in  the  R  Fl  until  all  volatile  substances  are  driven  off,  the  remaining 
mass  reduced  to  powder,  well  calcined,  and  the  calcined  mass  treated 
with  Bx  on  Ch  in  the  0  Fl.  If  cobalt  is  the  only  coloring  metal  present, 
the  bead  will  exhibit  a  pure  blue  color ;  a  small  addition  of  iron  will 
make  the  glass  appear  green  while  hot,  but  blue  when  cold.  Copper  and 
nickel,  when  present  to  some  extent,  will  prevent  the  cobalt-color  to  be 
distinctly  seen.  The  bead  is  in  this  case  exposed  to  the  R  Fl  until  it 
appears  transparent  and  flows  quietly ;  the  oxides  of  copper  and  nickel 
are  by  this  means  reduced,  and  the  pure  color  of  cobalt,  or  that  of  cobalt 
mixed  with  iron,  becomes  apparent. 
Copper. 

The  reactions  of  copper  and  its  compounds,  see  $$  35,  36,  and  Table 
11,8. 

§71.  The  red  color  which  copper  imparts  to  the  Bx  orSPh  bead, 
when  heated  on  Ch  in  the  R  Fl  in  contact  with  tin  (v.  Table  II,  8),  is 
very  characteristic  and  will  in  most  cases  clearly  show  the  presence  of 
this  metal.  But  if  only  a  small  quantity  of  copper  is  associated  with 
other  metals,  the  reaction  is  not  easily  obtained ;  in  this  case  we  may 
proceed  as  follows  : 

The  assay  [No.  89,  or  No.  86,  or  No.  85]  is  placed  on  Ch  and  played 
upon  with  the  0  Fl  until  antimony  and  other  volatile  metals  are  driven 
off.  Some  vitrified  boracic  acid  is  fused  on  Ch  to  a  glassy  globule,  the 


40 


assay  placed  close  to  it,  and  the  whole  covered  with  a  large  R  Fl.  When 
the  metallic  globule  begins  to  assume  a  bright  metallic  surface,  the  flame 
is  gradually  converted  into  a  sharply-pointed  blue  cone,  which  is  made 
to  act  only  on  the  glass,  leaving  the  metallic  globule  untouched,  and  so 
situated  that  it  touches  the  glass  on  one  side,  and  on  the  other  side  is  in 
close  contact  with  the  Ch.  During  this  process  lead,  iron,  cobalt,  part 
of  the  nickel,  and  such  of  the  more  volatile  metals,  that  were  not  entirely 
removed  by  the  previous  calcination,  as  bismuth,  antimony,  zinc,  &c., 
become  oxidized,  and  their  oxides  partly  volatilized  and  partly  absorbed 
by  the  boracic  acid.  The  remaining  metallic  globule  is  then  removed 
from  the  flux  and  treated  on  Ch  with  S  Ph  in  the  0  Fl,  when  the  copper 
is  oxidized  and  dissolved.  The  limpid  bead  is  then  refused  in  the  RF1 
with  addition  of  tin.  A  trace  of  copper  may  thus  be  made  to  produce 
distinctly  the  characteristic  reaction. 

$  72.  To  show  the  presence  of  copper  in  compounds  which  contain 
much  nickel,  cobalt,  iron,  and  arsenic,  the  assay  [No.  82]  is  first  treated 
with  Bx  on  Ch  in  the  R  Fl,  when  the  greater  part  of  iron  and  cobalt  are 
dissolved.  The  remaining  globule  is  then  mixed  with  some  pure  lead, 
and  treated  as  shown  $  71.  Arsenic  is  for  the  most  part  driven  off,  and 
the  rest  of  the  iron  and  cobalt,  with  some  nickel,  absorbed  by  the  boracic 
acid.  The  globule  is  removed  from  the  glass  and  treated  with  S  Ph  in 
the  0  Fl ;  dark-green  while  hot,  and  somewhat  lighter  green  when  cold 
(produced  by  the  mixture  of  the  yellow  of  nickel  and  the  blue  of  copper), 
indicates  the  presence  of  copper. 

To  detect  copper  when  in  combination  with  tin  v.  $  110. 

£  73.  To  detect  copper  in  sulphides,  the  pulverized  assay  [No.  7G]  is 
calcined,  and  the  calcined  mass  treated  as  above,  or,  when  the  amount 
of  copper  is  not  very  small,  simply  treated  with  Bx  or  S  Ph  on  Ch  in  the 
0  Fl,  and  subsequently  with  addition  of  tin  in  the  R  Fl.  The  presence 
of  copper  is  then  shown  by  the  red  color  and  the  opaqueness  of  the  glass 
on  cooling.  This  reaction  is  only  prevented  or,  at  least,  made  indistinct 
by  antimony  or  bismuth,  which  cause  the  glass  to  turn  gray  or  black. 
In  this  case  the  assay  is,  after  calcination,  mixed  with  Sd,  Bx,  and  some 
pure  lead,  and  the  mixture  fused  on  Ch  in  the  R  Fl.  The  metallic  glo- 


41 


bule  is  then  heated  on  Ch  to  drive  off  the  antimony,  and  afterwards 
treated  with  boracic  acid  as  above. 

§  74.  When  a  mineral  which  contains  copper  is  heated  in  the  blue 
cone,  the  outer  cone  of  the  flame  frequently  assumes  a  green  or,  if  the 
metal  is  in  combination  with  chlorine,  an  azure-blue  color.  This  reac- 
tion, if  not  produced  by  heating  the  substance  alone,  may  sometimes  be 
elicited  by  adding  a  drop  of  concentrated  hydrochloric  acid  to  the  pul- 
verized assay  [No.  73],  evaporating  to  dryness,  mixing  the  dry  powder 
with  a  little  water  to  a  stiff  paste,  fastening  this  into  the  hook  of  a  pla- 
tinum wire,  and  then  exposing  it  to  the  blue  cone  of  the  flame. 

Fluorine. 

$  75.  To  detect  fluorine  in  such  minerals  where  it  occurs  only  as  an 
accessory  element  in  combination  with  weak  bases,  and  which  at  the 
same  time  contain  water,  a  small  piece  of  the  substance  [No.  60]  is 
placed  into  a  glass  tube  sealed  at  one  end,  a  wet  Brazil-wood  paper  in- 
troduced into  the  open  end,  and  heat  applied.  Fluoride  of  silicon  and 
hydrofluoric  are  evolved ;  the  former  is  decomposed  by  the  watery  vapor 
and  deposits  a  ring  of  silica  not  far  distant  from  the  assay,  and  the  lat- 
ter turns  the  red  color  of  the  test-paper  into  straw-yellow.  Mica, 
containing  not  more  than  f  per  cent,  of  fluorine  shows  the  reaction  very 
distinctly. 

$  76.  To  show  the  presence  of  fluorine  in  minerals  where  it  is  united 
with  strong  bases,  the  finely  powdered  assay  [No.  6]  is  mixed  with  about 
four  parts  of  bisulphate  of  potassa  and  introduced  into  a  glass  tube, 
sealed  at  one  end.  Heat  is  applied  until  sulphuric  acid  begins  to  escape. 
The  sides  of  the  tubes  become  covered  with  silicic  acid,  resulting  from  the 
decomposition  of  the  gaseous  fluoride  of  silicon.  The  tube  is  cut  off 
close  above  the  fused  mass,  cleaned  with  water,  and  carefully  dried  with 
blotting  paper.  The  dulled  appearance  of  the  glass  indicates  the  pre- 
sence of  fluorine. 

2J7.  Another  process,  and  by  which  the  presence  of  fluorine  in  all 
kind  of  compounds  may  be  shown,  is  to  mix  the  pulverized  assay  with 
some  S  Ph  which  has  previously  been  fused  on  Ch  and  then  reduced  to 
powder ;  to  place  the  mixture  on  platinum  foil,  which  is  connected  with 


an  open  glass  tube  in  such  a  manner  as  to  constitute  a  kind  of  tubular 
continuation  to  the  former,  and  to  heat  with  the  blowpipe  flame  until  the 
mass  enters  into  fusion.  If  the  flame  is  so  directed  that  the  products  of 
decomposition  are  made  to  pass  through  the  glass  tube  and  a  moistened 
Brazil-wood  paper  is  introduced  into  the  other  end,  the  presence  of  hy- 
drofluoric acid  is  indicated  by  the  change  of  color  which  the  latter  expe- 
riences ;  in  some  cases  the  glass  will  also  be  dulled,  or  a  deposit  of  silicic 
acid  be  formed.  This  test  is  very  delicate. 

Gold. 

\  78.  When  gold  is  in  combination  with  metals  which  are  volatile  at 
a  high  temperature,  ex.  gr.  tellurium,  mercury,  antimony,  it  is  only  ne- 
cessary to  heat  the  alloy  on  Ch  with  the  0  Fl,  when  the  gold  remains 
behind  in  a  pure  state  and  may  be  recognized  by  its  physical  properties. 
Lead  is  removed  by  the  process  of  cupellation,  as  explained  in  $  102. 

|  79.  When  associated  with  copper,  the  presence  of  which  is  easily 
detected  by  S  Ph  on  Ch,  the  alloy,  for  example  gold-coin,  is  dissolved  in 
pure  melted  lead  and  the  new  compound  subjected  to  the  process  of 
cupellation  on  bone-ash.  Copper  is  by  this  means  entirely  removed.  To 
test  the  remaining  globule  for  silver,  it  is  treated  with  S  Ph  on  Ch  in  the 
0  Fl ;  the  silver  is  gradually  oxidized  and  dissolved  by  the  glass,  which 
when  cold  assumes  an  opal-like  appearance.  To  determine  approxi- 
mately the  relative  proportions  of  the  two  metals,  the  metallic  globule  is 
taken  from  the  cupel,  placed  in  a  small  porcelain  dish,  containing  some 
nitric  acid,  and  heat  applied.  If  the  alloy  contains  25  per  cent,  of  gold 
or  less,  it  turns  black,  the  silver  is  gradually  dissolved  and  the  gold  re- 
mains behind  as  a  brown  or  black  spongy  or  pulverulent  mass.  If  the 
alloy  contains  more  than  25  per  cent,  of  gold,  the  globule  turns  also 
black,  but  the  silver  is  not  dissolved.  If  both  metals  are  present  in 
about  equal  proportions,  the  globule  remains  unaltered.  If  the  amount 
of  gold  is  considerable  it  is  indicated  by  the  color  of  the  alloy. 

\  80.  When  associated  with  metals,  which  per  se  are  infusible  before 
the  blowpipe,  as  ex.  gr.  platinum,  iridium,  palladium,  the  metallic  glob- 
ule obtained  by  cupellation  shows  much  less  fusibility  than  pure  gold. 
The  exact  nature  of  the  foreign  metals  cannot  be  ascertained  before  the 
Blp ;  the  humid  way  must  be  resorted  to. 


Iodine. 

%  81.  Iodides,  tested  with  a  SPh  bead  which  is  saturated  with  oxide 
of  copper  as  shown  $  65,  impart  to  the  outer  flame  a  fine  green  color 
[No.  17]. 

Fused  with  bisulphate  of  potassa  in  a  glass  tube,  closed  at  one  end, 
violet  vapors  are  evolved,  iodine  sublimes,  and  sulphurous  acid  escapes. 

$  82.  Another  method,  which  is  said  to  surpass  in  delicacy  even  the 
reaction  with  starch,  is  to  mix  the  substance  with  a  mixture  of  carbonate 
of  lime  and  quicklime,  to  dry  the  mass  thoroughly,  to  add  some  proto- 
chloride  of  mercury  (corrosive  sublimate),  to  rub  the  whole  well  together, 
and  to  place  it  in  a  glass  tube  closed  at  one  end.  The  tube  is  then  nar- 
rowly drawn  out  a  little  above  the  assay,  and  the  mass  heated  to  redness. 
Protiodide  of  mercury  is  formed,  which  sublimes  in  yellow  or  red  needles 
into  the  narrow  tube.  This  reaction  is  founded  on  the  property  of  lime 
to  decompose  the  protochloride  of  mercury,  but  not  the  protiodide. 
Iron. 

The  reactions  of  the  oxides  of  iron,  see  Table  II,  10. 

g  83.  The  colors  which  iron  imparts  to  the  various  fluxes  are  suffi- 
ciently characteristic  to  ascertain  its  presence  in  such  metallic  compounds 
which  contain  no  easily  fusible  substances,  by  simply  treating  the  assay 
with  Bx  on  Ch  in  the  0  Fl.  When  lead,  tin,  bismuth,  antimony,  or  zinc 
are  present,  the  R  Fl  is  employed,  and  directed  in  such  a  manner  that  it 
principally  touches  the  glass.  Thus,  the  oxidation  and  consequent  satu- 
ration of  the  bead  with  the  oxides  of  these  metals,  is  to  a  great  extent 
prevented.  In  either  case  the  glass,  while  still  soft,  is  removed  from  the 
globule  and  exposed  on  another  place  of  the  Ch  to  the  R  Fl.  Those 
metals  whose  oxides  are  easily  reduced,  are  now  precipitated,  and  the 
characteristic  bottle-green  color  of  iron  is  clearly  observable,  unless  cobalt 
be  present.  In  this  case  the  glass  is  again  softened  with  the  R  Fl,  sepa- 
rated from  the  precipitated  metals,  fastened  into  the  hook  of  a  platinum 
wire  and  treated  with  the  0  Fl  until  the  whole  of  the  iron  may  be  sup- 
posed to  be  converted  into  sesquioxide.  The  glass,  while  hot,  will  appear 
green,  and  blue  when  cold,  if  only  a  trace  of  iron  is  present.  But  when 
the  amount  of  iron  is  more  considerable,  it  will  be  dark-green  while  hot 


and  bright-green  when  cold,  the  latter  color  resulting  from  the  mixture 
of  the  blue  of  cobalt  and  the  yellow  of  iron.  The  metals  remaining  be- 
hind on  Ch  after  the  treatment  with  Bx,  and  which  frequently  are  only 
copper  and  nickel  (lead,  antimony,  and  bismuth  being  volatilized),  may 
be  treated  as  shown  $71. 

To  detect  iron  in  arsenides  and  sulphides,  the  assay  is  well  calcined, 
and  the  calcined  mass  treated  as  above  [No.  86  and  No.  79]. 

\  84.  The  oxides  of  iron  when  associated  with  a  large  quantity  of  man- 
ganese [No.  84  and  No.  69],  color  the  Bx  bead  on  platinum  wire  in  the 
0  Fl,  red.  To  show  the  presence  of  iron  the  bead  is  removed  from  the 
wire,  placed  on  Ch,  and  treated  with  tin  in  the  R  Fl.  The  vitriol-green 
color  of  iron  will  appear  in  its  purity.  When  associated  with  the  oxides 
of  manganese  and  cobalt,  a  minute  quantity  of  iron  cannot  very  well  be 
detected  by  means  of  the  blowpipe  alone.  When  accompanied  by  the 
oxides  of  copper  and  nickel  [No.  78  or  No.  85],  the  assay  is  dissolved 
in  Bx  on  Ch  in  the  0  Fl  and  the  glass  treated  as  shown  §  83. 

$  85.  The  presence  of  chromium  prevents  any  conclusive  deduction  as 
to  the  presence  of  iron  from  the  color  of  the  beads.  In  such  a  case  the 
substance  [No.  71]  may  be  mixed  with  three  parts  of  nitre  and  one  of 
Sd,  and  the  mixture  fused  in  small  portions  into  the  hook  of  a  thick 
platinum  wire.  The  alkaline  chromate  is  dissolved  in  water  and  the  resi- 
due treated  with  the  fluxes.  The  presence  of  the  oxides  of  iron  when 
associated  with  the  oxides  of  uranium  cannot  be  ascertained  by  means 
of  the  blowpipe  alone. 

Lead. 

The  reactions  of  lead  and  its  compounds,  see  \\  12,  23,  36,  and  Table 
II,  12. 

$  86.  An  alloy  of  lead  and  zinc  [No.  50]  deposits  a  Ct  of  oxide  of  lead 
mixed  with  oxide  of  zinc  ;  the  presence  of  lead  is  shown  by  the  color 
of  the  Ct  and  by  the  azure-blue  tinge  which  it  imparts  to  the  RF1  (v. 
2  23). 

An  alloy  of  lead  and  bismuth  [No.  49]  deposits  a  Ct  somewhat  darker 
than  that  of  pure  lead,  in  which  the  presence  of  bismuth  may  be  detected 
as  shown  $  59,  and  the  presence  of  lead  by  the  azure-blue  color  of  the 
RF1. 


45 


$  87.  To  detect  lead  in  sulphides,  the  substance  is  placed  on  Ch  and 
treated  with  the  R  Fl ;  the  lead  is  detected  by  its  Ct.  An  admixture  of 
antimony  cannot  by  this  means  be  ascertained,  since  the  ring  of  sulphate 
of  lead,  surrounding  that  of  the  oxide,  bears  a  striking  resemblance  to 
the  Ct  formed  by  antimonous  acid.  In  this  case  the  pulverized  assay 
[No.  85]  is  mixed  with  a  sufficient  quantity  of  Sd,  and  treated  for  a 
short  time  with  the  E,  Fl.  If  no  antimony  is  present  a  pure  yellow  Ct 
with  bluish-white  edges  is  formed ;  but  in  presence  of  antimony  this  Ct 
is  surrounded  by  another,  white  one,  of  antimonous  acid.  The  oxide  of 
lead  Ct  appears,  moreover,  darker  than  usual,  resembling  that  of  bis- 
muth, owing  probably  to  the  formation  of  antimonate  of  lead.  If  this 
Ct  is  scraped  off  from  the  Ch  and  treated  with  S  Ph  as  mentioned  \  59, 
in  the  case  of  bismuth,  the  bead,  on  cooling,  assumes  a  black  color, 
whereby,  in  absence  of  bismuth,  the  presence  of  antimony  is  proved.  A 
very  small  quantity  of  antimony  can  by  this  method  not  be  found  out 
with  certainty,  since,  by  keeping  up  the  blast  for  some  time,  the  sulphide 
of  sodium  begins  to  vaporize  and  to  coat  the  Ch  with  a  ring  of  sul- 
phate of  soda  (v.  $  30). 

§  88.  When  sulphide  of  lead  is  associated  with  a  considerable  quan- 
tity of  sulphide  of  copper  [No.  89],  the  metallic  globule,  obtained  by 
the  process  of  reduction,  does  not  betray,  by  its  physical  properties,  the 
presence  of  lead.  But  if  the  alloy  is  removed  from  the  flux  and  played 
upon  with  a  powerful  0  Fl,  the  greater  part  of  the  lead  will  be  volatilized 
and  deposit  a  Ct. 

Lithia. 

$  89.  To  detect  lithia  in  silicates  which  contain  only  little  of  it,  pro- 
ceed as  follows:  The  substance  [No.  G7]  is  reduced  to  a  fine  powder 
and  mixed  Avith  about  2  parts  of  a  mixture  of  1  part  of  fluorspar  with  1£ 
parts  of  bisulphate  of  potassa ;  a  few  drops  of  water  are  added  and  the 
whole  kneaded  into  a  paste.  The  mass  is  fused  with  the  blue  cone  of 
the  flame  into  the  hook  of  a  platinum  wire.  If  lithia  is  present  the  outer 
flame  will  appear  red.  The  color  is  not  very  intense,  and  verging  into 
violet.  The  presence  of  potassa  does  not  prevent  the  reaction,  but  makes 
the  flame  appear  still  more  violet ;  soda  makes  the  reaction  uncertain. 


46 
Manganese. 

The  reactions  of  manganese,  see  Table  II,  13. 

$  90.  The  presence  of  manganese  in  any  compound  substance  is  readily 
detected  by  mixing  the  pulverized  assay  [No.  6G  or  No.  84]  with  about 
2  or  3  parts  of  Sd;  and  fusing  it  by  means  of  the  0  Fl  on  platinum  foil. 
Manganate  of  soda  is  formed,  which,  while  hot,  is  green  and  transparent 
and,  on  cooling,  turns  bluish-green  and  opaque.  The  reaction  is  very 
distinct  when  as  much  as  one-tenth  per  cent,  of  manganese  is  present. 
But  even  the  slightest  trace  may  be  detected  when,  instead  of  Sd,  a  mix- 
ture of  1  part  of  nitre  with  2  parts  of  Sd  is  used.  Chromium  does  not 
prevent  the  reaction,  merely  changing  the  color  to  yellowish-green.  It 
is  only  in  presence  of  silica  and  cobalt  that  this  test  is  not  available, 
since  at  a  high  temperature  the  silica  unites  with  the  soda  to  silicate  of 
soda,  which,  in  dissolving  the  oxide  of  cobalt,  produces  a  blue  glass,  and 
thus  interferes  with  the  manganese  color. 
Mercury. 

The  reactions  of  mercury  and  its  compounds,  see  $$  11,  17,  and  Table 
II,  14. 

$  91.  Mercury  is  detected  in  amalgams  [No.  47]  by  the  sublimate  of 
metallic  mercury  which  they  yield,  when  heated  in  a  glass  tube  closed  at 
one  end. 

When  in  combination  with  sulphur  [No.  81],  chlorine  [No.  39],  iodine 
or  ox-acids,  the  substance  is  previously  mixed  with  some  anhydrous  Sd 
or  some  neutral  oxalate  of  potassa.  The  acids,  &c.,  are  retained  by  the 
soda,  and  mercury  sublimes. 

If  the  quantity  of  mercury  is  so  small,  that  the  nature  of  the  sublimate 
cannot  with  certainty  be  ascertained,  the  experiment  has  to  be  repeated, 
a  piece  of  iron  wire  around  which  a  gold-leaf  has  been  wrapped  being  at 
the  same  time  introduced  into  the  tube  and  held  close  above  the  assay. 
The  gold-leaf  will  turn  white  if  ever  so  little  mercury  be  present. 

Nickel. 

The  reactions  of  nickel,  see  Table  II,  16. 

§  92.  To  detect  nickel  in  metallic  compounds  which  are  fusible  before 
the  Blp,  the  assay  is  treated  with  Bx  on  Ch  in  the  R  Fl ;  iron,  cobalt, 


47 


&c.,  enter  into  the  flux  and  may  be  detected  as  shown  $  69,  while  the 
metals  whose  oxides  are  easily  reduced  remain  behind.  This  operation 
is  repeated  until  the  glass  appears  no  longer  colored.  The  remaining 
globule  is  treated  with  S  Ph  in  the  0  Fl.  We  now  obtain  either  the 
pure  color  of  nickel,  or  that  of  nickel  mixed  with  copper  (v.  $  72) ; 
in  this  case  it  is  treated  on  Ch  with  tin,  whereby  the  presence  of  copper 
may  be  ascertained.  Bismuth  or  antimony  prevents  the  reaction  for 
copper,  the  bead  turning  black,  instead  of  red.  Such  compounds  must, 
previous  to  their  treatment  with  fluxes,  be  heated  on  Ch  in  R  Fl  until  all 
volatile  substances  are  driven  off  [No.  82]. 

In  arsenides  and  sulphides  nickel  is  detected  by  the  methods  given  for 
cobalt  under  the  same  circumstances  (v.  $  70). 

Nitric  acid. 

|  93.  The  perfectly  dry  substance  [No.  23]  is  heated  in  a  matrass 
with  some  bisulphate  of  potassa ;  orange-yellow  vapors  of  nitrous  acid 
are  emitted,  even  if  but  a  small  quantity  of  a  nitrate  is  present. 

Phosphoric  acid. 

%  94.  A  very  minute  quantity  of  phosphoric  acid  may  be  detected  by 
pulverizing  the  substance  [No.  14],  adding  a  drop  of  concentrated  sul- 
phuric acid,  fastening  the  paste  into  the  hook  of  a  platinum  wire,  and 
playing  upon  it  with  the  blue  cone  of  the  flame ;  the  outer  flame  will 
assume  a  bluish-green  color  (v.  $  35). 

Certain  azotized  compounds,  as  nitric  acid,  nitrate  of  ammonia, 
chloride  of  ammonium,  &c.,  when  fastened  into  the  hook  of  a  platinum 
wire  and  touched  with  the  cone  of  the  blue  flame,  impart  to  the  outer 
flame  a  bluish-green  color,  resembling  that  caused  by  phosphoric  acid. 

g  95.  In  a  substance,  containing  not  less  than  about  5  per  cent. of  phos- 
phoric acid,  the  presence  of  the  latter  may  be  shown  by  dissolving  the 
assay  [No.  68]  on  Ch  in  boracic  acid  and  forcing  into  the  glass,  when  a 
good  fusion  is  effected,  a  piece  of  fine  steel  wire  ;  a  good  R  Fl  is  then 
given.  The  iron  is  oxidized  at  the  expense  of  the  phosphoric  acid, 
causing  the  formation  of  a  borate  of  the  oxide  of  iron  and  phosphide  of 
iron,  which  fuses  at  a  sufficiently  high  temperature.  The  bead  is  then 
taken  from  the  Ch,  enveloped  in  a  piece  of  paper,  and  struck  lightly  with 


48 


a  hammer,  by  wliicli  means  the  phosphide  of  iron  is  separated  from  the 
surrounding  flux.  It  exists  as  a  metallic-looking  button,  attractable  by 
the  magnet,  frangible  on  the  anvil,  the  fracture  having  the  color  of  iron. 
If  the  substance  under  assay  contained  no  phosphoric  acid,  the  iron  wire 
will  keep  its  form  and  metallic  lustre,  excepting  at  the  ends,  where  it  will 
be  oxidated  and  burnt.  The  substance  to  be  assayed  ought  not  to  con- 
tain sulphuric  acid,  arsenic  acid,  or  any  metallic  oxides  reducible  by 
iron. 

Phosphate  of  lead  exhibits  the  peculiarity  of  crystallizing  on  cooling 
after  having  been  fused  on  Ch ;  the  crystals  have  frequently  large  facets 
of  a  pearly  lustre. 

Potassa. 

$  97.  The  violet  color  of  the  flame  is  sufficiently  characteristic  for  potassa 
(v.  \  33).  But  being  altogether  prevented  or,  at  least,  made  very  indis- 
tinct by  the  addition  of  a  few  per  cent,  of  soda  or  lithia,  it  can  only  in  a 
very  few  cases  be  made  use  of.  For  the  detection  of  potassa  in  silicates 
it  is  almost  entirely  unavailable,  because  these  compounds  almost  always 
contain  some  soda. 

$  98.  If  the  base  of  a  compound  consists  essentially  of  potassa,  the  fol- 
lowing method  may  be  advantageously  employed  for  its  detection  :  Some 
Bx,  to  which  a  little  boracic  acid  has  been  added,  is  melted  into  the  hook 
of  a  platinum  wire  and  so  much  protoxide  of  nickel  added  that  the  glass 
on  cooling  shows  a  distinct  brownish  color.  A  small  piece  of  the  sub- 
stance under  examination  [No.  15]  is  made  to  adhere  to  the  glass  and 
the  whole  fused  together  with  the  0  Fl.  If  the  assay-piece  contained  no 
potassa,  the  color  of  the  glass,  after  perfect  cooling,  will  have  remained 
unchanged ;  but  if  potassa  was  present  in  sufficient  quantity,  the  glass 
will  appear  bluish. 

Selenium. 

$  99.  The  reactions  of  selenium  are  very  characteristic.  In  non-volatile 
compounds,  which  do  not  give  the  red  sublimate  mentioned  $  11,  the 
selenium  is  detected  by  heating  a  small  piece  of  the  substance  [No.  87] 
on  Ch  in  0  Fl,  when  the  peculiar  odor  is  evolved ;  if  much  selenium  is 
present,  a  Ct  is  deposited,  v.  §  28.  Selenites  and  selenates  are  treated  on 


49 


Ch  with  Sd  in  R  Fl,  when  a  reduction  takes  place  and  the  selenium  va- 
porizes with  the  characteristic  odor. 

Silica. 

I  100.  Pure  silica  [No.  54],  when  treated  with  Bx  on  platinum  wire, 
dissolves  slowly  to  a  transparent  glass  which  fuses  with  difficulty.  Treated 
with  S  Ph  in  the  same  manner  only  a  small  quantity  is  dissolved,  the  rest 
floating  in  the  liquid  bead  as  a  semi-transparent  mass.  The  behavior  to 
Sd  see  g  39.  With  a  little  So  Co  it  assumes  a  pale  bluish  color  which, 
on  addition  of  a  large  quantity  of  the  reagent,  turns  dark-gray  or  black; 
very  thin  splinters  may  be  fused  by  a  great  heat  to  a  reddish-blue  glass. 

$  101.  Silicates  [No.  61],  when  treated  with  SPh  on  platinum  wire, 
are  decomposed  ;  the  bases  unite  with  the  free  phosphoric  acid  to  a  trans- 
parent glass  in  which  the  silica  may  be  seen  floating  as  a  gelatinous 
cloudy  mass.  The  bead  ought  to  be  carefully  observed  while  hot,  since 
many  silicates  form  a  glass  which  on  cooling  opalizes  or  becomes  opaque, 
when,  of  course,  the  phenomenon  can  no  longer  be  seen.  The  experi- 
ment is  best  performed  with  a  small  splinter  of  the  substance  under  ex- 
amination, and  only  when  this  does  not  appear  to  be  affected  by  the  flux, 
the  finely  pulverized  substance  should  be  used.  If  but  a  very  small 
quantity  of  silica  is  present,  the  glass  will  appear  perfectly  transparent. 
Its  presence  in  this  case  cannot  be  detected  by  means  of  the  Blp. 

\  102.  Silicates  containing  at  least  so  much  silica  that  the  quantity  of 
oxygen  in  the  acid  is  twice  that  of  the  oxygen  in  the  base,  dissolve,  when 
treated  with  Sd  on  Ch,  with  effervescence  to  a  transparent  glass  which 
remains  so  when  cold.  When  less  silica  is  present  decomposition  also 
takes  place,  but  the  glass  turns  opaque  on  cooling,  the  amount  of  silicate 
of  soda  which  is  formed  not  being  sufficient  to  dissolve  the  eliminated 
bases. 

Silver. 

The  reactions  of  silver,  see  §27,  and  Table  II,  20. 

$  103.  When  in  combination  with  metals  which  are  volatile  at  a  high 
temperature,  ex.  gr.  bismuth,  lead,  zinc,  antimony,  the  substance  is  heated 
alone  on  Ch,  when,  after  evaporation  of  the  foreign  metals,  a  button  of 
pure  silver  remains  behind  and  a  feeble  reddish  Ct  is  deposited  on  the  Ch. 


50 


If  associated  with  much  lead  or  bismuth,  these  metals  are  best  removed 
by  cupellation,  a  process  which  is  executed  in  the  following  manner : 
Finely  pulverized  bone-ash  is  mixed  with  a  minute  quantity  of  soda  and 
made  with  a  little  water  into  a  stiff  paste  ;  a  hole  is  now  bored  into  the 
Ch;  filled  with  the  paste,  and  its  surface  smoothed  and  made  slightly 
concave  by  pressing  on  it  with  the  pestle  of  the  little  agate  mortar.  The 
mass  is  then  dried  by  the  flame  of  a  common  spirit-lamp.  On  this  little 
cupel  the  assay  [No.  51]  is  placed  and  so  long  heated  with  the  0  Fl  until 
the  whole  of  the  lead  or  bismuth  is  oxidized  and  absorbed  by  the  cupel. 
The  silver  or,  if  gold  is  present,  the  alloy  of  silver  and  gold  remains  as  a 
bright  metallic  button  on  the  cupel. 

$  104.  When  combined  with  metals  which  are  not  volatile,  but  which 
are  easier  oxidized  than  silver,  the  presence  of  this  metal  may  in  some 
cases  be  detected  by  simply  treating  the  alloy  with  Bx  or  SPh  on  Ch. 
Copper,  nickel,  cobalt,  &c.,  become  oxidized  and  their  oxides  dissolved 
by  the  flux,  while  silver  remains  behind  with  a  bright  metallic  surface. 
But  when  these  metals  are  present  to  a  considerable  extent,  another 
course  has  to  be  pursued,  a  course  which  may  always  be  taken  when  a 
substance  is  to  be  assayed  for  silver,  or  silver  and  gold. 

$  105.  The  assay-piece  [No.  86]  is  reduced  to  a  fine  powder,  mixed 
with  vitrified  Bx  and  metallic  lead  (the  quantities  of  which  altogether 
depend  upon  the  nature  of  the  substance,  and  for  which,  therefore,  no 
general  rule  can  be  given),  and  the  mass  placed  in  a  cylindrical  hole  of 
the  Ch.  A  powerful  R  Fl  is  given  until  the  metals  have  united  to  a  but- 
ton, and  the  slag  appears  free  from  metallic  globules.  The  flame  is  now 
converted  into  a  0  Fl  and  directed  principally  upon  the  button.  Sulphur, 
arsenic,  antimony,  and  other  very  volatile  substances,  are  volatilized ; 
iron,  tin,  cobalt,  and  a  little  copper  and  nickel  become  oxidized  and  are 
absorbed  by  the  flux  ;  silver  and  gold  and  the  greater  part  of  copper  and 
nickel  remain  with  the  lead  (and  bismuth,  if  present).  When  all  vola- 
tile sabstances  are  driven  off,  the  lead  begins  to  become  oxidized,  and 
the  button  assumes  a  rotary  motion ;  at  this  period  the  blast  is  discon- 
tinued, the  assay  is  allowed  to  cool,  and  when  perfectly  cold  the  lead 
button  is  separated  from  the  glass  by  some  slight  strokes  with  a  hammer. 


51 


It  is  now  placed  on  a  cupel  of  bone-ash  and  treated  with  the  0  Fl  until 
it  again  assumes  a  rotatory  motion.  If  much  copper  or  nickel  is  present, 
the  globule  becomes  covered  with  a  thick  infusible  crust,  which  prevents 
the  aimed-at  oxidation ;  in  this  case  another  small  piece  of  pure  lead  has 
to  be  added.  The  blast  is  kept  up  until  the  whole  of  the  lead  and  other 
foreign  metals,  viz.,  copper  and  nickel,  are  oxidized ;  this  is  indicated  by 
the  cessation  of  the  rotatory  movement,  if  only  little  silver  is  present,  or 
by  the  appearance  of  all  the  tints  of  the  rainbow  over  the  whole  surface 
of  the  button,  if  the  ore  was  very  rich  in  silver ;  after  a  few  moments  it 
takes  the  look  of  pure  silver.  The  oxides  of  lead,  copper,  &c.,  are  ab- 
sorbed by  the  bone-ash,  and  pure  silver,  or  an  alloy  of  silver  with  other 
noble  metals,  remains  behind ;  the  button  may  be  tested  for  gold,  &c., 
after  the  method  given  in  $  79. 
Sulphur. 

\  106.  The  presence  of  sulphur  in  sulphides  may  in  many  cases  be 
detected  by  heating  in  a  glass  tube  (v.  $  11,  14),  or  on  Ch  with  the 
OF1. 

\  107.  A  very  delicate  test  for  the  presence  of  sulphur,  in  whatever 
combination  it  may  be  contained  in  the  substance,  and  which  possesses 
moreover  the  advantage  over  all  other  methods  of  being  very  easily  per- 
formed, is  to  mix  the  pulverized  assay  [No.  4]  with  some  pure  Sd  or, 
better  still,  with  a  mixture  of  2  parts  of  Sd  and  1  of  Bx,  and  to  treat  it 
on  Ch  with  the  RF1.  The  fused  mass  is  removed  from  the  Ch,  pow- 
dered, the  powder  placed  on  a  silver  foil  or  a  bright  silver  coin,  and  a 
drop  of  water  added.  If  the  substance  under  examination  contained  any 
sulphur,  a  black  spot  will  be  formed  on  the  silver  foil,  owing  to  the  forma- 
tion of  sulphide  of  silver  from  the  decomposition  of  the  sulphide  of  so- 
dium, which,  in  its  turn,  resulted  from  the  decomposition  of  the  sulphide 
or  sulphate,  or  other  sulphur-compound  of  the  assay-piece,  under  the  in- 
fluence of  Sd,  Ch,  and  a  high  temperature.  Selenium  shows  the  same 
reaction  ;  it  is  readily  recognized  by  the  peculiar  odor  which  it  emits 
when  heated  on  Ch  alone. 

$  108.  To  decide  whether  the  reaction  obtained  in  the  experiment  was 
owing  to  the  presence  of  a  sulphide  or  to  that  of  a  sulphate,  the  finely- 


52 


pulverized  substance  [No.  76]  is  fused  in  a  small  platinum  spoon  with 
some  hydrate  of  potassa.  The  spoon  with  the  contents  is  then  placed 
into  a  vessel  containing  some  water,  and  a  piece  of  silver  foil  inserted 
into  the  liquid.  If  the  silver  remains  perfectly  bright,  a  sulphate  was 
present,  if  it  turns  black,  a  sulphide.  The  absence  of  substances  which 
might  exercise  a  reducing  influence  is  required. 
Tellurium. 

\  109.  The  presence  of  tellurium  in  mineral  substances  is  detected  by 
the  tests  given  $§11,18,29.  In  presence  of  lead  or  bismuth  the 
reactions  in  the  open  tubes  and  on  Ch  are  not  quite  pure.  In  this  case 
we  may  subject  the  assay  to  the  following  treatment:  The  substance  is 
mixed  with  some  Sd  and  charcoal-powder,  the  mixture  introduced  into  a 
glass  tube  closed  at  one  end,  and  heated  to  fusion ;  after  cooling,  a  few 
drops  of  hot  water  are  poured  into  the  tube ;  if  tellurium  was  present, 
telluride  of  sodium  has  been  formed,  which  dissolves  in  hot  water  with  a 
purplish-red  color.  This  test  is  applicable  to  show  the  presence  of  tellu- 
rium in  a  great  many  compounds,  even  in  such  where  it  occurs  in  the 
oxidized  state. 
Tin. 

The  reactions  of  tin  and  its  compounds,  see  $  12,  26,  45,  and 
Table  II,  22. 

§  110.  The  presence  of  tin  is  indicated  by  its  Ct  when  the  substance 
[No.  13]  alone  or  mixed  with  Sd,  is  exposed  to  the  E  Fl  on  Ch. 

When  the  substance  under  examination  is  an  alloy,  a  little  Bx  is  con- 
veniently added,  which  absorbs  the  oxide  of  tin  in  the  measure  as  it  is 
formed,  and  allows  the  presence  of  those  metals  which  are  more  volatile, 
ex.  gr.  antimony,  lead,  bismuth,  to  be  recognized  by  their  coatings. 
Arsenic  is  detected  by  its  odor,  and  iron  by  the  color  which  the  Bx  bead 
assumes  when  refused  on  platinum  wire  in  the  0  Fl. 

To  detect  copper  in  tin  or  its  alloy,  the  assay  [No.  52]  is  fused  with 
a  flux  consisting  of  100  parts  of  Sd,  50  of  vitrified  Bx,  and  30  of  silica. 
The  flame  is  so  directed  that  the  metallic  globule  assumes  a  rotatory 
motion.  When  in  this  state  the  glass  is  kept  covered,  as  much  as  possi- 
ble, with  the  0  Fl,  care  being  taken  that  the  globule  is  at  one  side  in 


53 


contact  with  the  glass,  and  at  the  other  with  the  Ch.  The  tin  becomes 
oxidized  and  the  oxide,  in  the  measure  as  it  is  formed,  absorbed  by  the 
flux ;  the  remaining  button  is  copper,  pure  or  with  a  small  quantity  of 
tiu,  and  may  be  readily  tested  with  the  usual  fluxes. 

Titanium. 

$111.  Titanic  acid,  when  forming  the  principal  constituent  of  any 
mineral  substance,  is  easily  detected  by  its  behavior  with  the  fluxes,  v. 
Table  II,  23 ;  but  when  in  combination  with  bases  these  reactions  are 
not  always  clearly  perceptible,  being  frequently  suppressed  by  the  pre- 
dominating reaction  of  the  base.  In  such  cases  we  may  subject  the 
assay  to  the  following  treatment,  by  which  even  very  small  quantities  of 
titanic  acid  will  become  apparent :  the  substance  [No.  65]  is  reduced  to 
a  very  fine  powder,  mixed  with  from  6  to  8  parts  of  bisulphate  of  potassa, 
and  fused  in  a  platinum  spoon  at  a  low  red-heat ;  the  fused  mass  is  dis- 
solved in  a  porcelain  vessel  in  the  smallest  possible  quantity  of  water, 
aided  by  heat.  There  remains  an  insoluble  residue  which  is  allowed  to 
settle  ;  the  clear  liquid  is  poured  off  into  a  larger  vessel,  mixed  with  a 
few  drops  of  nitric  acid  and  at  least  six  volumes  of  water,  and  heated  to 
ebullition.  If  the  substance  under  examination  contained  any  titanium, 
a  white  precipitate  of  titanic  acid  forms  on  boiling.  The  precipitate  is 
collected  on  a  filter,  washed  with  water,  acidulated  with  nitric  acid,  and 
tested  with  S  Ph. 
Uranium. 

$  112.  The  presence  of  this  metal  is  easily  recognized,  in  substances 
which  contain  no  other  coloring  constituents,  by  the  reactions  given  Table 
II,  25  ;  the  most  characteristic  test  is  that  with  S  Ph.  In  presence  of 
much  iron  this  reaction  becomes  indistinct ;  we  may  then  operate  in  the 
following  manner :  the  finely-pulverized  substance  [No.  70]  is  fused  with 
bisulphate  of  potassa,  the  fused  mass  dissolved  in  water,  mixed  with  car- 
bonate of  ammonia  in  excess,  the  liquid  separated  from  the  precipitate 
by  filtration,  and  the  filtrate  heated  to  ebullition.  If  any  uranium  was 
present,  a  yellow  precipitate  is  thrown  down,  which  gives  with  the  fluxes 
the  pure  reactions  of  uranium. 


Zinc. 

The  reactions  for  zinc  and  its  compounds,  see  $  12,  25,  45,  and 
Table  II,  27. 

§  113.  A  small  amount  of  zinc,  when  associated  with  considerable 
quantities  of  lead,  or  bismuth,  or  antimony,  or  tin,  cannot  with  certainty 
be  ascertained  by  means  of  the  Blp. 

If  the  substance  under  examination  contains  the  zinc  as  oxide  [No. 
36],  or  but  a  small  quantity  of  sulphide,  it  is  mixed  with  Sd  and  treated 
on  Ch  in  R  Fl.  Substances  consisting  essentially  of  sulphide  of  zinc 
may  be  thus  treated  without  the  addition  of  Sd,  and  such  as  contain, 
beside  oxide  of  zinc,  other  metallic  oxides,  are  conveniently  mixed  with 
some  Sd  to  which  about  one-half  of  its  weight  of  Bx  has  been  added.  A 
ring  of  oxide  of  zinc  is  deposited  on  the  Ch.  When  lead  is  present 
[No.  51]  the  Ct  is  frequently  not  pure,  being  mixed  up  with  the  Ct  of 
lead.  In  this  case  it  is  moistened  with  some  So  Co  and  heated  again  with 
the  0  Fl.  The  oxide  of  lead  is  reduced  by  the  red  hot  Ch  and  vola- 
tilized, while  the  oxide  of  zinc  remains  behind  with  a  green  color 
(v.  g  45). 


FOURTH  CHAPTER, 


CHARACTERISTICS   OF   THE   MOST  IMPORTANT   ORES; 

THEIR  BEHAVIOR  BEFORE  THE  BLOWPIPE, 

AND  TO  SOLVENTS. 

$  114.  OF  the  physical  properties  of  the  minerals  which  are  treated  of 
in  this  chapter,  only  those  are  enumerated  which  serve  best  to  discrimi- 
nate the  different  ores  from  each  other.  For  a  more  detailed  description 
I  must  refer  to  Dana's  and  other  works  on  mineralogy.  Among  the 
distinguishing  characters  of  minerals,  their  hardness  and  specific  gravity 
stand  foremost.  The  latter  cannot  be  ascertained  without  a  good  balance, 
and  will,  for  this  reason,  be  of  much  less  use  to  the  practical  man  than 
the  determination  of  hardness,  an  operation  which  may  be  performed  in 
a  few  moments.  A  set  of  minerals,  representing  the  scale  of  hardness, 
being  not  always  at  hand,  it  will  be  useful  to  give  a  series  of  substitutes 
for  them,  as  arranged  by  Mr.  Chapman  : 

1.  Yields  easily  to  the  nail. 

2.  Yields  with  difficulty  to  the  nail,  or  merely  receives  an  impression 
from  it.     Does  not  scratch  a  copper  coin. 

3.  Scratches  a  copper  coin;  but  is  also  scratched  by  it,  being  of  about 
the  same  degree  of  hardness. 

4.  Not  scratched  by  a  copper  coin  ;  does  not  scratch  glass. 

5.  Scratches  glass,  though  rather  with  difficulty,  leaving  its  powder  on 
it.     Yields  readily  to  the  knife. 


56 


6.  Scratches  glass  easily.     Yields  with  difficulty  to  the  knife. 

Y.  Does  not  yield  to  the  knife.  Yields  to  the  edge  of  a  file,  though 
with  difficulty. 

8.  9.  10.  Harder  than  flint. 

The  scale  of  hardness,  as  introduced  by  Mohs,  and  enlarged  by 
Breithaupt,  is  as  follows : 

1.  Talc;  common  laminated  light-green  variety. 

2.  Gypsum  ;  a  crystalline  variety. 
2.5.  Foliated  Mica. 

3.  Calcareous  Spar ;  transparent  variety. 

4.  Fluor  Spar ;  crystalline  variety. 

5.  Apatite  ;  transparent  variety. 
5.5.  Scapolite  ;  crystalline  variety. 

6.  Orthoclase  ;  white  cleavable  variety. 

7.  Quartz  ;  transparent. 

8.  Topaz;  transparent. 

9.  Sapphire  ;  cleavable  varieties. 

10.  Diamond. 

To  test  the  hardness  of  a  mineral  we  may  proceed  in  two  different 
manners  :  firstly,  by  attempting  to  scratch  it  with  the  minerals  enume- 
rated in  the  scale,  successively,  or,  secondly,  by  abrasion  with  a  file.  If 
the  file  abrades  the  mineral  under  trial  with  the  same  ease  as  No.  4,  and 
produces  an  equal  depth  of  abrasion  with  the  same  force,  its  hardness  is 
said  to  be  4.  If  with  more  facility  than  4,  but  less  than  5.  the  hardness 
may  be  4£  or  4£.  Several  successive  trials  should  be  made  to  obtain 
certain  results;  and,  when  practicable,  both  methods  should  be  em- 
ployed. 

ORES  OF  ANTIMONY. 

Gray  Antimony  [Stibnite]. 

§  115.  Sb  S3.  H=2.  G=4.5.  Of  lead-gray  color  and  metallic  lustre. 
Usually  of  columnar  structure,  consisting  of  a  vast  number  of  needle- 
shaped  crystals,  sometimes  side  by  side,  sometimes  divergent.  Very 
brittle. 


57 


It  fuses  readily  in  the  flame  of  a  candle.  In  a  matrass,  sometimes 
yields  a  slight  sublimate  of  sulphur ;  on  increasing  the  heat  by  application 
of  the  Blp  flame,  a  sublimate  is  produced  which  after  cooling  is  brownish- 
red,  and  which  consists  of  a  mixture  of  tersulphide  of  antimony  with 
antimonous  acid.  In  an  open  glass  tube,  emits  sulphurous  acid  and 
antimonial  fumes.  On  Ch  it  is  volatilized,  covering  the  Ch  with  oxide 
of  antimony,  which,  when  touched  with  the  R  Fl,  disappears  with  a  pale 
greenish- blue  tinge. 

When  pure,  wholly  soluble  in  heated  hydrochloric  acid  with  evolution 
of  sulphuretted  hydrogen  ;  usually  a  residue  of  chloride  of  lead  is  left. 
Partly  decomposed  by  caustic  potassa;  the  solution,  when  mixed  with  an 
acid,  affords  a  yellowish-red  precipitate. 

Berthierite. 

g  116.  Composition  variable,  sometimes  Fe  S  +  Sb  S3.  H=2— 3. 
G=4 — 4.3.  Metallic  lustre,  less  splendent  than  gray  antimony  j  color 
dark  steel-gray. 

Heated  in  a  matrass,  fuses  and  yields  a  slight  sublimate  of  sulphur ; 
on  application  of  a  strong  heat,  a  black  sublimate  of  sulphide  of  anti- 
mony is  formed,  which,  on  cooling,  becomes  brownish-red.  In  an  open 
glass  tube  it  behaves  like  the  preceding  ore.  In  Ch,  fuses  easily  and 
coats  the  charcoal  with  oxide  of  antimony ;  there  remains,  finally,  a  black 
slag,  which  is  attracted  by  the  magnet  and  gives  with  fluxes  the  iron 
reaction. 

Soluble  in  hydrochloric  acid. 

Red  Antimony  [Kermesite]. 

1 117.  2  SbS3+  SbO3.  H=l— 1.5.  G=4.5— 4.6.  Usually  in  tufts  of 
capillary  crystals  of  cherry-red  color. 

In  a  matrass,  fuses  readily  and  yields  a  slight  yellowish-red  sublimate  ; 
with  strong  heat,  boils  and  gives  a  black  sublimate  which,  when  cold,  is 
brownish-red.  In  an  open  tube  and  on  Ch,  behaves  like  gray  antimony. 

It  dissolves  in  hydrochloric  acid  with  evolution  of  sulphuretted  hydro- 
gen. The  powdered  mineral,  when  treated  with  caustic  potassa,  assumes 
an  ochre-yellow  color  and  dissolves  completely. 


58 

ORES  OP  ARSENIC. 

Native  Arsenic. 

|  118.  As,  with  traces  of  Sb,  Ag,  Fe,  Co  and  Ni.  H=3.5.  G=5.9. 
Of  metallic  lustre  and  tin-white  color,  tarnishing  on  exposure  to  air  to 
dark-gray. 

Heated  in  a  matrass,  sublimes ;  on  Ch,  behaves  like  pure  arsenic.  In 
both  cases,  sometimes,  a  residue  is  left,  which,  when  treated  with  lluxes, 
exhibits  the  reactions  of  iron,  cobalt  and  nickel.  (See  f 83.) 

Realgar. 

1 119.  As  S«.  H=1.5— 2.  G=3.4— 3.6.    Usually  of  bright-red,  some- 
times of  orange-yellow  color,  and  resinous  lustre.    Sectile. 

In  a  matrass,  fuses,  boils,  and  finally  sublimes ;  the  sublimate,  iit'ter 
cooling,  is  red  and  transparent.  In  an  open  glass  tube,  when  carefully 
heated,  yields  a  sublimate  of  ajrsenous  acid,  sulphurous  acid  escaping. 
On  Ch,  {uses  readily  and  burns  with  a  yellowish-white  flame,  emitting 
grayish-white  fumes  which  possess  the  peculiar  alliaceous  odor.  Sub- 
jected to  the  treatment  described  $  55,  a  sublimate  of  metallic  arsenic  is 
obtained. 

Not  easily  affected  by  acids ;  but  aqua  regia  dissolves  it  with  continued 
digestion,  part  of  the  sulphur  being  precipitated.     A  heated  solution  of 
caustic  potassa  decomposes  it,  leaving  a  brownish-black  powder  (As6  S) 
undissolved. 
Orpiment. 

1 120.  AsS3.  H=1.5 — 2.    G=3.4.     A  foliaceous  mineral  of  lemon- 
yellow  color,  and  resinous  or  pearly  lustre.     Sectile. 

Before  the  Blp,  behaves  like  the  preceding,  with  this  difference,  that 
the  sublimate,  after  cooling,  is  dark  yellow  and  transparent. 
Soluble  in  aqua  regia,  caustic  potassa,  and  ammonia. 
White  Arsenic  [Arsenolite]. 

1 121.  AsO8.   H=1.5.   G=3.6.     Occurs  usually  in  minute  capillary 
crystals  of  a  white  color,  and  vitreous  or  silky  lustre. 

Before  the  Blp  it  behaves  like  pure  arsenous  acid.  (v.  $  9,  15,  Table 
II,  2). 


Slightly  soluble  in  hot  water ;  more  so  in  water  acidulated  with  hydro- 
chloric acid. 

ORES  OF  BISMUTH. 

Native  Bismuth. 

%  122.  Bi;  H=2— 2.5.  G=9.7.  Color  silver-white,  tinged  with  red. 
Lustre  metallic.  Brittle  when  cold ;  but,  when  hot,  may  be  laminated. 
Occurs  foliated,  granular,  and  arborescent ;  occasionally  crystallized. 

Before  the  Blp  it  behaves  like  pure  bismuth  (v.  \\  17,  22). 

Readily  dissolved  by  nitric  acid ;  the  solution  is  precipitated  by  water. 
Telluric  Bismuth  [Tetradymite]. 

g  123.  Bi  and  Te  in  variable  proportions.  H=1.5 — 2.  G=7.2 — 8.4. 
Of  pale  steel-gray  color,  and  high  metallic  lustre.  Occurs  usually  in 
tabular  crystals,  or  foliated  masses;  the  larainas  are  elastic.  It  soils 
paper. 

In  an  open  glass  tube  it  fuses  readily,  emitting  a  white  smoke  which 
partly  condenses,  coating  the  tube  near  the  assay-piece  with  a  white  pow- 
der, intermixed  with  red  spots  ;  on  directing  the  flame  on  this  Ct,  it  fuses 
to  colorless  drops  (TeO2),  while  the  red  sublimate  (Se)  disappears.  On 
Ch,  fuses  instantly  to  a  metallic  globule  which,  when  touched  with  the 
inner  flame,  imparts  a  bluish-green  color  to  the  outer  one,  sometimes 
gives  out  selenium  vapors,  and  deposits,  close  to  the  assay-piece,  a  dark 
orange  Ct,  surrounded  at  a  greater  distance  by  a  white  Ct. 

Soluble  in  nitric  acid. 

Bismutite. 

§124.  3(BiO*.C02+HO)-hBi03.HO.  H=4— 4.5.  G=6.9.  Usually 
of  a  white  or  light  greenish  color,  and  vitreous  lustre;  in  acicular  crys- 
tallizations. 

In  a  matrass,  decrepitates,  yields  a  little  water,  and  turns  gray.  Ou 
Ch,  fuses  very  readily  and  is  reduced,  with  effervescence,  to  a  metallic 
globule,  covering  the  Ch  with  a  Ct  of  oxide  of  bismuth.  If  the  blast  is 
kept  up  for  some  time  the  whole  of  the  bismuth  is  volatilized  and  there 
remains  a  scoriaccous  mass  which,  in  the  R  Fl,  may  be  fused  to  a  gobule, 


60 


and  which  with  fluxes  gives  the  indications  of  copper  and  iron.    With  Sd 
it  usually  gives  the  sulphur  reaction  ($  107). 

Dissolves  in  hydrochloric  acid  with  effervescence;  the  solution  has  a 
yellow  color. 
Bismuthine. 

$  125.  Bi  S3.  11=2— 2-5.  G=6.4— 6.55.  In  acicular  crystals  or  mas- 
sive ;  of  metallic  lustre,  and  lead-gray  color,  with  a  yellowish  or  iridescent 
tarnish. 

In  a  matrass,  fuses  and  yields  a  slight  sublimate  of  sulphur.  Care- 
fully heated  in  an  open  tube,  it  fuses  and  yields  sulphurous  acid  and  a 
coat  of  sulphate  of  bismuth;  the  latter  may  be  fused,  by  application  of 
the  Blp  flame,  to  brown  drops  which,  when  cold,  appear  yellow  and 
opaque.  On  Ch,  fuses  and  boils,  throwing  out  small  drops  in  a  state  of 
incandescence,  and  deposits  a  Ct  of  oxide  of  bismuth. 

Soluble  in  nitric  acid  with  deposition  of  sulphur.  The  solution  gives 
a  white  precipitate  with  water. 

Bismuth  Ochre. 

%  126.  BiO3,  containing  minute  quantities  of  Fe203,  CuO,  and  AsO.5 
G=4.36.  Occurs  usually  pulverulent  or  earthy. 

Before  the  Blp  it  behaves  like  pure  oxide  of  bismuth.  Soluble  in  ni- 
tric acid. 

ORES  OF  CHROMIUM. 

Chromic  Iron. 

§  127.  (FeO,  CrO,  MgO)  +  (Cr2  O3,  Al2  O3).  H=5.5.  G=4.3— 46.  Oc- 
curs usually  massive ;  of  iron-black  or  brownish-black  color,  with  a 
shining  and  somewhat  metallic  lustre.  Some  varieties  are  magnetic. 

Heated  in  a  matrass,  remains  unchanged.  Infusible  in  the  forceps. 
After  having  been  exposed  to  the  R  Fl  it  follows  the  magnet.  In  Bx 
and  SPh  slowly,  but  completely,  soluble  to  a  transparent  glass,  which  is 
beautiful  green  after  cooling.  Mixed  with  Sd  and  nitre  and  heated  on 
platinum-foil,  the  mass  fuses  and  becomes  yellow.  With  Sd  on  Ch  in 
II  Fl  it  affords  metallic  iron. 


61 


Concentrated  acids  affect  it  but  little,  even  when  finely  pulverized ; 
they  dissolve  only  a  little  iron.  Fused  with  caustic  potassa,  chromate  of 
potassa  is  formed. 

ORES  OF  COBALT. 

Smaltine. 

$  128.  (Co,  Fe,  Ni)  As.  H=3.5— 6.  0=6.4—7.2.  Of  tin- white  or  steel- 
gray  color,  and  metallic  lustre. 

In  a  matrass,  usually  yields,  when  heated  to  redness,  a  sublimate  of 
metallic  arsenic.  In  an  open  glass-tube,  affords  a  copious  sublimate  of 
crystallized  arsenous  acid,  and  sometimes  emits  sulphurous  acid.  On  Ch 
it  fuses  readily,  with  emission  of  copious  arsenical  fumes,  to  a  grayish- 
black  magnetic  globule  which,  with  the  fluxes,  gives  the  indications  of 
iron,  cobalt,  and  nickel. 

With  nitric  acid  it  gives  a  pink  solution,  arsenous  acid  being  deposited. 
Oolaltine. 

§129.  CoS2-fCoAs.  H=5.5.  G=6— 6.3.  Of  silver-white  and  some- 
times reddish  color,  and  metallic  lustre. 

Unchanged  in  the  matrass.  In  an  open  glass  tube,  yields  a  sublimate 
of  arsenous  acid  and  vapors  of  sulphurous  acid.  On  Ch,  emits  copious 
arsenical  and  sulphur  fumes  and  fuses  to  a  dull  black  metallic  globule, 
which  is  attracted  by  the  magnet,  and  which,  when  treated  with  fluxes, 
gives  the  indications  of  cobalt  and  iron,  and  sometimes  also  those  of 
nickel. 

Dissolves  in  heated  nitric  acid,  arsenous  acid  being  deposited. 
Cobalt  Pyrites  [Linnaeite]. 

1 130.  CoS+Co2S3.  H=5.5.  G=4.8— 5.  Of  a  more  or  less  bright 
steel-gray  color,  and  metallic  lustre.  Crystallizes  in  the  regular  octahe- 
dron. 

In  an  open  glass  tube,  sulphurous  acid  is  abundantly  evolved  and  some- 
times a  slight  sublimate  of  arsenous  acid  formed.  On  Ch,  small  pieces 
of  the  mineral  readily  fuse  to  a  globule  which,  when  cold,  is  covered  with 
a  black  rough  crust,  and  which  is  attracted  by  the  magnet.  The  pulver- 

6 


62 


ized  mineral,  after  having  been  well  calcined,  dissolves  in  Bx  in  OF1  to 
a  blue  transparent  glass.  In  a  highly  saturated  bead  of  this  kind,  when 
treated  on  Ch  with  RF1,  particles  of  metallic  nickel  may  be  seen  floating 
about. 

Soluble  in  nitric  acid,  excepting  the  sulphur. 
Cobalt  Bloom  [Erythrine]. 

§131.  3CoO.  As05+8HO.  H=1.5— 2.5.  G— 2.9.  Usually  of  crim- 
son or  peach-red  color ;  when  crystallized,  of  pearly  lustre ;  frequently  dull 
and  earthy,  forming  incrustations. 

Heated  in  a  matrass,  loses  water,  and  the  color  changes  to  blue  or 
green.  A  small  crystal,  exposed  to  the  inner  flame,  fuses  and  colors  the 
outer  flame  pale-blue.  On  Ch  in  RF1,  emits  arsenical  fumes  and  melts 
to  a  dark-gray  globule  of  arsenide  of  cobalt  which,  with  fluxes,  gives  the 
pure  cobalt-reactions. 

Acids  dissolve  it  readily  to  a  rose-colored  liquid ;  the  solution  in  con- 
centrated hydrochloric  acid  appears  blue,  while  hot.  The  pulverized 
mineral  is  partly  decomposed  by  caustic  potassa ;  the  powder  assumes  a 
bluish-gray  color  and  the  solution  is  sapphire-blue. 

Lavendulan. 

\  132.  AsO5,  CoO,  NiO,  CuO,  and  HO.  H=2.5— 3.  G=3.  Amor- 
phous, with  a  greasy  lustre ;  color  lavender-blue. 

Heated  in  a  matrass,  gives  out  water.  In  the  forceps,  fuses  easily  and 
colors  the  outer  flame  pale-blue  ;  the  fused  mass  becomes  crystalline  on 
cooling.  On  Ch  in  RF1  it  fuses  with  emission  of  arsenical  fumes.  With 
fluxes,  gives  the  reactions  of  Co,  Ni,  and  Cu  (see  \  92). 

Earthy  Cobalt. 

\  133.  It  is  a  variety  of  Wad  (see  §  184),  containing  sometimes  a  con- 
siderable quantity  of  oxide  of  cobalt,  in  combination  with  silicic  or  arsenic 
acid. 

With  Bx  in  OF1,  gives  a  dark-violet  glass,  which  in  the  RF1  becomes 
blue.  The  SPli  bead  when  treated  on  Ch  with  metallic  tin  frequently 
exhibits  the  copper-reaction,  With  Sd  on  platinum-foil  it  shows  the  pres- 
ence of  manganese, 


Soluble  in  hydrochloric  acid  with  evolution  of  chlorine ;  the  solution  is 
usually  blue,  and  on  addition  of  water  becomes  red. 

ORES  OF  COPPER. 

Native  Copper. 

1 134.  Pure  Copper.     H=2.5— 3.   G=8.9.     Of  metallic  lustre,  and 
copper-red  color.     Occurs  usually  massive  or  arborescent. 

It  fuses  on  Ch  to  a  globule  which,  if  the  heat  is  sufficiently  high,  as- 
sumes a  bright  bluish-green  surface  ;  on  cooling  it  becomes  covered  with 
a  crust  of  black  oxide.  With  the  fluxes  it  gives  the  usual  indications  of 
copper. 

It  dissolves  readily  in  nitric  acid. 
Copper  Pyrites  [Chalcopyrite]. 

1 135.  Cu2S  +  Fe'S3.  H=3.o— 4.  0=4.1—4.3.  Of  a  brass-yellow  color 
and  metallic  lustre ;  on  exposure  to  moist  air  it  becomes  iridescent  on  its 
surface.  It  occurs  crystallized,  but  usually  massive.  It  is  easily  scratched 
with  a  knife,  giving  a  greenish-black  powder. 

Heated  in  a  matrass,  decrepitates  and  yields  sometimes  a  faint  subli- 
mate of  sulphur,  assuming  at  the  same  time  a  darker  color  or  becoming 
irridescent.  Heated  in  an  open  glass  tube,  sulphurous  acid  is  given  out 
abundantly.  On  Ch,  when  heated,  it  blackens,  but  becomes  red  on  cool- 
ing ;  with  continued  heat  it  fuses  to  a  black  globule,  which  is  attracted 
by  the  magnet  j  this  globule  is  brittle  and  reddish-gray  in  the  fracture. 
The  pulverized  mineral,  after  roasting,  gives  with  fluxes  the  indications 
of  iron  and  copper.  With  Sd  on  Ch  it  is  reduced  j  the  metals  are  ob- 
tained in  separate  masses.  Moistened  with  hydrochloric  acid  it  colors 
the  flame  blue,  even  previous  to  fusion. 

It  dissolves  in  nitric  acid  and,  more  readily,  in  aqua  regia,  leaving  a 
residue  of  sulphur. 

Purple  Copper  [Erubescite]. 

§  136.  3  Cu2  S  +  Fe2  S3.H=3.  0=4.4—5.  When  crystalline,  it  usually 
affects  the  cubical  form,  and  is  of  a  pale  yellowish  color;  when  massive, 
its  color  is  copper-red  to  reddish-brown  5  it  speedily  tarnishes,  assuming 


various  hues,  mostly  purple,  blue,  and  reddish.    When  scratched  with  a 
knife  it  gives  a  grayish  powder. 

Before  the  Blp  it  shows  pretty  much  the  same  behavior  as  copper 
pyrites. 

Concentrated  hydrochloric  acid  dissolves  it,  leaving  the  greater  part  of 
the  sulphur  behind. 
Copper  Crlance. 

1 137.  Cu2S.  H=2.5— 3.  0=5.5-5.8.  Of  a  blackish  lead-gray  color, 
often  with  a  bluish  or  greenish  tint  on  its  surface.  Occurs  usually  in 
compact  masses,  very  often  shining. 

Heated  in  a  matrass,  nothing  volatile  is  given  out.  In  an  open  tube, 
sulphurous  acid  is  evolved.  On  Ch,  readily  fuses  to  a  globule,  which 
boils,  and  emits  glowing  drops,  sulphurous  acid  escaping  abundantly ; 
the  outer  flame  is  at  the  same  time  colored  blue.  With  Sd  on  Ch  it 
yields  a  globule  of  metallic  copper. 

In  heated  nitric  acid  it  dissolves,  leaving  a  residue  of  sulphur. 

Gray  Copper  [Tetrahedrite]. 

§  138.  4(Cu2S.  FeS.  ZuS)  (SbS3.  AsS3)  frequently  containing  silver 
and  mercury.  H=3 — 4.5.  G=4.5 — 5.  Color  between  steel-gray  and 
iron-black. 

Heated  in  a  matrass,  fuses  and  finally  yields  a  dark-red  sublimate  of 
tersulphide  of  antimony  with  antimonous  acid.  In  an  open  glass  tube, 
fuses  and  gives  thick  fumes  of  antimony  (and  arsenous  acid),  and  sul- 
phurous acid ;  mercury,  when  present,  condenses  in  the  upper  part  of 
the  tube,  forming  a  metallic  mirror.  On  Ch  it  fuses  readily  to  a  globule, 
emitting  thick  white  fumes  and  sulphur  vapor;  coatings  of  antimonous 
acid  and  of  oxide  of  zinc  are  deposited  j  the  latter  is  nearer  to  the  assay- 
piece  and  may  be  tested  with  SoCo  [v.  $  45].  To  detect  arsenic,  v.  $  56. 
To  detect  mercury,  add  to  the  finely  pulverized  assay^hree  times  its 
weight  of  dry  Sd  and  treat  the  mixture  as  directed  §  91.  The  pulverized 
mineral,  after  having  been  well  roasted,  gives  with  the  fluxes  the  indica- 
tions of  iron  and  copper  j  with  Sd,  affords  metallic  copper  and  a  little 
iron.  To  detect  silver,  treat  the  mineral  with  pure  lead  and  Bx  as 
directed  2  105. 


65 


When  pulverized  it  is  decomposed  by  nitric  acid,  the  solution  has  a 
brownish-green  color;  antimonous  acid  (and  arsenous  acid)  and  sulphur 
remain  undissolved.  Caustic  potassa  effects  partial  decomposition  ;  the 
sulphide  of  antimony  (and  arsenic)  enters  into  solution,  and  is,  on  addi- 
tion of  an  acid,  re-precipitated. 
Tennantite. 

§  139.  4(Cu%  FeS),  AsS3.  H=3.5— 4.  G=4.37— 4.5.  Always  crys- 
tallized j  metallic  lustre ;  color  blackish  lead-gray  to  iron-black. 

In  a  matrass,  gives  a  sublimate  of  tersulphide  of  arsenic.  In  an  open 
tube,  sulphurous  acid  and  a  sublimate  of  arsenous  acid.  On  Ch,  fuses 
easily  with  emission  of  sulphur  and  arsenic  vapors  to  a  dark-gray  globule, 
which  is  attracted  by  the  magnet.  The  pulverized  mineral  gives,  after 
calcination,  with  fluxes,  the  reaction  of  iron  and  copper. 

Arsenical  Copper  [Domeykite.] 

$  140.  Cu6As.  H=3 — 3.5.  Keniform,  massive,  or  disseminated  ;  lustre 
metallic ;  color  tin-white  ;  black  and  soft  when  impure. 

Heated  in  a  matrass,  yields  a  little  water  and  a  sublimate  of  arsenous 
acid ;  the  assay-piece  assumes  a  silver-white  color.  In  an  open  tube, 
affords  a  crystalline  sublimate  of  arsenous  acid.  On  Ch,  fuses  easily 
with  emission  of  a  strong  alliaceous  odor  to  a  yellowish  metallic  mass, 
which  gives  the  copper  reactions. 

Readily  soluble  in  nitric  acid;  decomposed  by  hydrochloric  acid,  me- 
tallic arsenic  remaining  undissolved. 

Atacamite. 

§141.  CuCl-f  3CuO  +  3HO.  H=3— 3.5.  G=4— 4.3.  Occurs  crys- 
talline, or  massive  lamellar;  color  various  shades  of  bright  green, 
sometimes  blackish-green. 

Heated  in  a  matrass,  gives  out  water  and  a  gray  sublimate,  which,  on 
cooling,  becomes  grayish-white ;  the  water  shows  acid  reaction.  On  Ch, 
fuses  readily,  colors  the  outer  flame  azure-blue,  and  is  finally  reduced  to 
a  globule  of  metallic  copper ;  two  coatings  are  deposited  on  the  Ch,  the 
one  grayish-white  and  the  other  brownish,  which,  on  being  played  upon 
with  the  RF1,  change  their  place  with  an  azure-blue  tinge. 

Easily  soluble  in  acids. 


66 

Red  Copper. 

1 142.  Cu20.  H=3.5— 4.  G=5.8— 6.  Usually  of  a  very  intense,  deep 
red  color,  occasionally  crimson-red ;  exceedingly  friable. 

Heated  in  the  pincers,  fuses  and  colors  the  outer  flame  emerald-green ; 
moistened  with  hydrochloric  acid  and  treated  in  the  same  manner,  the 
color  is  azure-blue.  On  Ch  it  blackens,  then  fuses  quietly,  and  finally 
yields  a  globule  of  metallic  copper  which,  on  cooling,  becomes  covered 
with  a  coating  of  black  oxide. 

Dissolves  readily  in  nitric  acid.  With  hydrochloric  acid  it  gives  a 
brownish  solution,  which  on  addition  of  water  is  decomposed,  a  white  pre- 
cipitate of  subchloride  of  copper  being  formed.  It  is  also  soluble  in 
ammonia :  the  solution  is  colorless  when  the  access  of  air  is  prevented  ; 
on  exposure  to  air  it  turns  blue. 

Malachite. 

§  143.  2CuO.C02+HO.  H=3.5— 5.  G=3.7— 4.  Occurs  usually 
in  the  shape  of  mammillated  concretions ;  the  interior  is  very  compact, 
and  lustre  shining,  in  the  fracture  sometimes  earthy,  sometimes  silky ; 
of  a  bright  green  color. 

Heated  in  a  matrass,  gives  out  water  and  turns  black.  On  Ch,  fuses 
to  a  globule,  and  affords  metallic  copper  when  the  heat  is  sufficiently 
high  ;  heated  in  the  forceps,  the  outer  flame  is  colored  green.  With 
fluxes  and  Sd  it  behaves  like  oxide  of  copper  (v.  Table  II,  8). 

It  dissolves  in  acids  with  effervescence  ;  also  soluble  in  ammonia. 

Azurite  [Blue  Malachite]. 

§  144.  2(CuO.C02)  +  CuO.  HO.  H=3.5.— 4.  G=3.5— 3.8.  Occurs 
usually  crystallized,  or  in  globular  masses  of  columnar  structure.  It 
is  easily  distinguished  by  its  fine  blue  color ;  either  earthy  or  vitreous  in 
lustre. 

Before  the  Blp,  and  to  solvents,  it  behaves  like  malachite. 
Copper  Vitriol  [Cyanosite]. 

1 145.  CuO.  S03+5HO.  H=2.5.  G=2.21.  Lustre  vitreous ;  color 
various  shades  of  blue  ;  taste  metallic  and  nauseous. 

Heated  in  a  matrass,  swells  up,  gives  out  water,  and  becomes  white. 
On  Ch,  colors  the  outer  flame  green,  fuses,  and  affords  a  button  of  metal- 


67 

lie  copper,  crusted  with  a  coat  of  sulphide.    After  calcination,  gives  with 
fluxes  the  reactions  of  copper,  sometimes  also  those  of  iron. 

Soluble  in  water;  a  polished  plate  of  iron  introduced  into  the  solution 
becomes  coated  with  copper. 

PhospliocJialcite. 

§146.  3CuO.P05  +  3(CuO.HO),  sometimes  2(3CuO.P05)  +  HO+ 
4(CuO.HO).  H=4.5— 5.  G=4— 4.4.  Occurs  both  crystallized  and 
massive.  Of  adamantine  lustre,  and  dark  emerald-green  or  blackish- 
green  color. 

In  a  matrass,  gives  out  water  and  blackens.  A  piece,  previously 
heated  in  a  matrass,  fuses  in  the  forceps  to  a  black  globule,  which  be- 
comes crystalline  on  cooling.  With  Bx  and  SPh,  behaves  like  oxide  of 
copper.  Strongly  heated  on  Ch  with  a  sufficient  quantity  of  Sd,  nearly 
all  the  copper  is  obtained  as  a  metallic  globule.  Mixed  with  an  equal 
volume  of  metallic  lead  and  fused  on  Ch,  a  globule  of  metallic  copper  is 
obtained,  surrounded  by  a  fused  mass  of  phosphate  of  lead,  which  on 
cooling  crystallizes. 

Soluble  in  nitric  acid,  and  in  caustic  ammonia. 
Olivenite. 

$  147.  3CuO.  (As05.P05)-f-CuO.HO.  H=3.  G=4.1— 4.4.  Crys- 
tallized, or  in  globular  and  reniform  masses,  of  indistinctly  fibrous  struc- 
ture. Color  usually  olive-green. 

In  a  matrass,  yields  a  little  water.  In  the  forceps,  fuses  to  a  globule 
and  colors  the  outer  flame  bluish-green ;  the  fused  mass  crystallizes  on 
cooling.  On  Ch,  fuses  with  detonation  and  emission  of  arsenical  vapors 
to  a  metallic  globule  j  the  globule  is  white  and  somewhat  brittle,  and 
covered  with  a  brown  scoria.  Fused  with  metallic  lead,  it  is  decomposed 
in  the  same  manner  as  the  preceding  ore. 

Dissolves  in  nitric  acid,  also  in  ammonia. 

Tyrolite. 

§H8.  [(3CuO.As05  +  8HO)  +  2(CuO.HO)]+CaO.C02.  H=l— 2. 
G=3.  Usually  reniform,  massive  ;  structure  radiate  foliaceous.  Color 
pale-green.  Very  sectile. 

Heated  in  a  matrass,  decrepitates,  yields  much  water,  and  blackens. 


68 


On  Oh,  fuses  with  emission  of  arsenical  vapors  to  a  gray  scoriaceous 
mass,  in  which  minute  globules  of  metallic  copper  occasionally  appear. 
When  the  mineral  is  fused  on  Ch,  with  addition  of  Sd  and  Bx,  until  the 
oxide  of  copper  is  completely  reduced  and  the  slag  dissolved  in  hydro- 
chloric acid,  a  solution  is  obtained  in  which  the  presence  of  lime  may  be 
shown  by  the  proper  reagents. 

Dissolves  in  nitric  acid  with  effervescence,  also  in  ammonia. 

Chrysocolla. 

\  149.  3CuO.  2Si03+6HO.  H=2— 3.  G=2.  Occurs  usually  as  an 
incrustation.  It  very  much  resembles  malachite ;  its  color  is  bluish- 
green,  and  it  is  remarkable  for  its  great  compactness ;  its  surface  is  very 
smooth,  giving  it  the  appearance  of  an  enamel  or  a  well-fused  slag. 

In  a  matrass,  yields  water  and  blackens.  In  the  forceps  infusible, 
coloring  the  outer  flame  intensely  green.  On  Ch  in  OF1  blackens,  in 
EF1  turns  red.  SPh  and  Bx  dissolve  it  with  the  usual  indications  of 
copper;  the  SPh  bead  shows  a  cloud  of  undissolved  silica.  With  Sd  on 
Ch,  affords  globules  of  metallic  copper. 

It  is  decomposed  by  acids,  silica  remaining  undissolved. 

ORES  OF  GOLD,  PLATINUM,  AND  IRIDIUM. 

Native  Cf-old. 

§  150.  Combination  of  Au  and  Ag  in  variable  proportions,  sometimes 
with  traces  of  Fe  and  Cu.  H=2.5— 3.  0=15.6—19.5.  Easily  distin- 
guished by  its  malleability,  its  cutting  like  lead,  its  high  specific  gravity, 
and  its  resistance  to  acids.  Color  and  streak  various  shades  of  gold-yel- 
low. It  usually  occurs  in  variously  contorted  and  branched  filaments, 
in  scales,  in  plates,  or  in  small  irregular  masses. 

On  Ch,  fuses  to  a  globule  which,  after  cooling,  has  a  bright  metallic 
surface.  With  SPh  in  OF1,  a  bead  is  formed  which  opalizes  on  cool- 
ing, or  becomes  opaque  and  yellow,  according  to  the  amount  of  silver 
which  it  contains. 

Eesists  the  action  of  heated  concentrated  nitric  acid;  soluble  only  in 
aqua  regia. 


69 


Grraphie  Tellurium  [Sylvanite.] 

\  151.  AgTe+2AuTe3.  H=1.5— 2.  G=5.7.  Of  metallic  lustre  and 
steel-gray  color.  Very  sextile. 

In  an  open  glass-tube,  yields  a  white  sublimate  which,  when  played 
upon  with  the  flame,  fuses  to  transparent  drops.  On  Ch,  fuses  to  a  dark- 
gray  globule,  depositing  at  the  same  time  a  white  Ct  which,  when  touched 
with  the  RF1,  disappears,  tinging  the  flame  bluish-green  (see  \%  29, 
35).  It  finally  affords  a  light-yellow  malleable  globule  of  metallic  lustre. 

Soluble  in  aqua  regia,  leaving  a  residue  of  chloride  of  silver.  The 
solution  gives  a  white  precipitate  with  water. 

Native  Platinum. 

$  152.  Pt,  usually  combined  with  a  little  Fe,  Ir,  Os,  Pd,  Rh,  and  some- 
times Cu  and  Pb. 

H=4 — 4.5.  G=16 — 19.  Usually  occurs  in  grains  of  silver- whitish 
or  gray  color,  malleable  and  ductile. 

Infusible  before  the  Blp  and  not  acted  upon  by  fluxes.  Soluble  only 
in  heated  aqua  regia.  The  solution  gives  a  yellow  granular  precipitate 
with  chloride  of  potassium. 

Osmium- Iridium  [Iridosmine]. 

I 153.  The  light  variety  IrOs3  and  IrOs4.  H=6— 7.  0=19.3—21.1. 
Occurs  usually  in  irregular  flattened  grains,  of  metallic  lustre  and  tin- 
white  color ;  but  little  malleable. 

Infusible  before  the  Blp ;  when  fused  with  nitre  in  a  matrass,  the  cha- 
racteristic osmium  odor  is  produced.  The  fused  mass  is  soluble  in 
water ;  the  solution  gives,  on  addition  of  nitric  acid,  a  green  precipitate. 
The  dark  varieties  lose  before  the  Blp  the  metallic  lustre  and,  when 
held  in  the  alcohol  flame,  impart  to  it  a  yellowish-red  color  and  great 
luminating  power. 

Not  visibly  affected  by  any  acid. 

ORES  OF  IKON. 
Meteoric  Iron. 

%  154.  Fe  with  variable  quantities  of  Ni  (from  1  to  20  per  cent.)  and 
traces  of  Co,  Mg,  Mn,  Sn,  Cu,  Cr,  Si,  C,  Cl,  S,  and  P.  11=4.5.  0=7.3— 


70 


7.8,  rarely  as  low  as  G.  Lustre  metallic ;  color  iron-gray ;  ductile ;  strongly 
attracted  by  the  magnet. 

Infusible.  On  Ch  with  Bx  or  SPh  gives  only  the  reactions  of  iron. 
To  detect  the  presence  of  the  other  heavy  metals,  the  assay-piece  must 
be  dissolved  in  aqua  regia,  the  liquid  mixed  with  ammonia  in  excess,  fil- 
tered, and  the  ammoniacal  filtrates  precipitated  with  sulphydrate  of  am- 
monia. The  precipitate  consists  of  the  sulphides  of  nickel,  cobalt,  man- 
ganese, and  copper,  which  may  be  collected  on  a  filter  and  treated  with 
Bx  on  Ch  as  described  §  70. 

Brown  Hematite  [Limonite]. 

I  155.  2Fe203.  3HO.  H=5— 5.5.  G=H.6— 4.  Of  a  dull  brownish- 
yellow  color,  earthy  or  semi-metallic  in  appearance,  and  often  in  mam- 
millary  or  stalactitic  forms. 

In  a  matrass,  yields  water,  and  red  sesquioxide  remains ;  in  platinum 
forceps,  fusible  on  the  edges  ;  gives  with  Bx  and  SPh  an  iron  reaction  ; 
the  clayey  varieties  treated  with  SPh  give  a  cloud  of  undissolved  silica ; 
treated  with  Sd  and  nitre  on  platinum  foil,  the  manganese  reaction  is 
almost  always  obtained. 

Specular  Iron  [Hematite]. 

g  15G.  Fe203.  H=5.5— 6.5.  G=4.5— 5.3.  Of  a  dark  steel-gray  or 
iron-black  color  and  usually  of  metallic  lustre  ;  its  powder  is  red. 

Infusible  alone ;  becomes  magnetic  after  roasting,  and  gives  the  usual 
indications  of  iron  with  the  fluxes  ;  its  powder  dissolves  readily  in  heated 
hydrochloric  acid.  Contains  sometimes  chromium  and  titanium,  which 
may  be  detected  by  the  processes  given  in  \\  68  and  111. 

Magnetic  Iron  Ore  [Magnetite]. 

\  157.  FeO.Fe203.  H=5.5— 6.5.  G=4.9— 5.2.  Its  color  is  iron- 
black,  with  a  shining  metallic  or  glimmering  lustre  ;  its  powder  is  black; 
it  is  strongly  attracted  by  the  magnet. 

It  fuses  with  difficulty,  and  gives  the  usual  reactions  of  iron  with  the 
fluxes ;  the  pulverized  mineral  dissolves  completely  in  hydrochloric  acid. 
Iron  Pyrites. 

%  158.  FeS2.  H=6 — 6.5.  G=4.8 — 5.     Occurs   commonly  in   cubes. 


71 


Usually  of  a  brass-yellow  color  and  metallic  lustre.  By  its  superior  hard- 
ness, not  yielding  to  the  knife,  and  emitting  sparks  when  struck  with 
steel,  it  may  be  distinguished  from  copper  pyrites. 

Heated  in  a  glass  tube  closed  at  one  end,  usually  emits  some  sulphur- 
etted hydrogen,  and  yields  a  sublimate  of  sulphur;  the  residue  is  attracted 
by  the  magnet.  Heated  on  Ch  with  the  OF1,  the  sulphur  burns  off  with 
a  blue  flame,  and  leaves  red  oxide  behind,  which,  when  treated  with  the 
fluxes,  gives  pure  iron  reactions.  But  slightly  affected  by  hydrochloric 
acid ;  nitric  acid  dissolves  it,  leaving  a  residue  of  sulphur. 
White  Iron  Pyrites  [Marcasite]. 

\  159.  FeS2.  H=6— 6.5.  G=4.6— 4.8.  Crystals  are  prismatic.  Color 
usually  light  bronze-yellow,  sometimes  inclined  to  green  or  gray ;  occurs 
frequently  in  radiated  masses  or  crest-like  aggregations.  Very  liable  to 
decomposition. 

Before  the  Blp  it  behaves  like  the  preceding. 

Magnetic  Pyrites  [Pyrrhotine]. 

|  160.  5FeS  +  Fe2S3.  H=3.5— 4.5.  G=4.4— 4.7.  Very  much  re- 
sembles common  iron  pyrites,  from  which  it  is  distinguished  by  its  infe- 
rior hardness,  and  by  being  slightly  attracted  by  the  magnet. 

Heated  in  a  matrass,  remains  unchanged ;  in  the  open  glass  tube, 
emits  sulphurous  acid  but  yields  no  sublimate.  On  Ch  in  RF1,  fuses  to 
a  globule,  which  is  covered  with  an  uneven  black  coating,  which  follows 
the  magnet,  and  which,  on  a  surface  of  fracture,  exhibits  a  yellowish 
crystalline  structure  and  metallic  lustre.  In  OF1  it  is  converted  into  red 
oxide. 

Soluble  in  hydrochloric  acid,  excepting  the  sulphur,  with  evolution  of 
sulphuretted  hydrogen. 

Arsenical  Pyrites  [Mispickel]. 

§161.  FeS2+FeAs.  H=5.5— 6.  G=5— 6.4.  Of  metallic  lustre  and 
a  silver-white  color.  Streak  dark  grayish-black.  Brittle. 

Heated  in  a  matrass,  yields  first  a  red  sublimate  of  sulphide  of  arsenic, 
and  afterwards  a  black  crystalline  one  of  metallic  arsenic  5  in  an  open 
glass  tube,  yields  arsenous  acid  and  sulphurous  acid.  On  Ch,  emits  co- 
pious arsenical  fumes,  and  a  Ct  of  arsenous  acid  is  deposited  ;  then  fuses 


72 

to  a  globule  which  shows  the  properties  of  fused  magnetic  pyrites.  Fre- 
quently contains  cobalt,  the  presence  of  which  may  be  detected  by  the 
method  described  in  g  69. 

Soluble  in  nitric  acid  and  aqua  regia,  leaving  a  residue  of  sulphur  and 
arsenous  acid  ;  the  latter  dissolves  with  continued  digestion. 

Titaniferous  Iron  [Ilmenite]. 

§  162.  Ti203  and  Fe203  in  various  proportions.  H=5— 6.  G=5.5— 5. 
Of  iron-black  color,  usually  in  tabular  crystals,  bears  a  great  resemblance 
to  specular  iron,  but  gives  no  red  powder. 

Alone  in  the  OF1  infusible ;  in  RF1  it  may  be  rounded  at  the  edges. 
With  Bx  and  SPh  in  OF1,  gives  the  reactions  of  pure  oxide  of  iron ; 
but  the  SPh  bead  when  treated  with  the  RF1  assumes  a  brownish-red 
color,  the  intensity  of  which  depends  upon  the  amount  of  titanic  acid 
present ;  this  glass,  when  treated  with  tin  on  Ch,  turns  violet  (v.  Table 
II,  23).  To  show  conclusively  the  presence  of  Ti,  follow  the  method 
given  in  $  111. 

Dissolved  by  hydrochloric  acid  and  aqua  regia  with  separation  of  titanic 
acid ;  some  varieties  dissolve  with  great  difficulty,  even  when  reduced  to 
a  very  fine  powder. 

Spathic  Iron  [Chalybite]. 

§  163.  FeO.  CO2.  H=3.5— 4.5.  G=3.7— 3.9.  Color  from  grayish-yel- 
low to  reddish-brown ;  crystallizes  in  rhombohedrons,  which  are  often 
curved,  and  are  very  distinctly  cleavable ;  often  massive. 

Heated  in  a  matrass,  frequently  decrepitates,  carbonic  acid  and  car- 
bonic oxide  are  given  out,  and  a  black  oxide  of  iron  remains,  which  is 
attracted  by  the  magnet.  Alone,  infusible.  With  Bx  and  SPh  it  gives 
the  pure  iron  reactions,  and  with  Sd  sometimes  those  of  manganese.  It 
dissolves  in  strong  acids  with  effervescence,  but  with  difficulty,  and  only 
when  pulverized. 

G-reen  Vitriol  [Copperas], 

§164.  FeO.S03+7HO.E=2.  G=1.83.  Occurs  usually  massive  and 
pulverulent,  of  various  shades  of  green,  becoming  yellowish  on  exposure 
to  air;  taste  astringent  and  metallic. 


In  a  matrass,  gives  out  sulphurous  acid  and  water,  which  shows  acid 
reaction.  Strongly  heated,  only  sesquioxide  of  iron  remains. 

Soluble  in  water. 
Vivianite. 

I  165.  6(3FeO,P05+8HO)  +  (3Fe203,2P05+8HO).  H=1.5— 2. 
G=2.66.  Occurs  crystallized,  or  in  reniform  and  globular  masses,  some- 
times as  incrustation.  Color  blue  to  green,  usually  dirty  blue. 

In  a  matrass,  swells  and  gives  pure  water.  In  the  forceps,  fuses  to 
a  steel-gray  metallic  globule,  coloring  the  outer  flame  bluish-green. 
With  fluxes  gives  the  reactions  of  iron. 

Easily  soluble  in  hydrochloric  acid  and  nitric  acid.     With  a  solution 
of  caustic  potassa,  it  blackens. 
tScorodite. 

$  166.  Fe203,As03+4HO.  H=3.5— 4.  G=3.1— 3.3.  Crystallized. 
Color  pale  leek-green  or  liver-brown. 

In  a  matrass,  yields  pure  water.  In  the  forceps,  fuses  to  a  gray  sco- 
riaceous  slag  of  metallic  lustre,  coloring  the  outer  flame  pale-blue.  On 
Ch,  emits  arsenical  vapors  and  fuses  to  a  gray  magnetic  slag,  of  me- 
tallic lustre,  which  gives  with  fluxes  the  reactions  of  iron. 

Not  affected  by  nitric  acid ;  forms  a  brown  solution  with  hydrochloric 
acid ;  partially  dissolved  by  ammonia,  leaving  a  brown  residue. 

ORES  OF  LEAD. 

Plumbic  Ochre. 

$  167.  PbO,  containing  frequently  PbO.CO2,  CaO,  Fe203,  and  SiO3. 
G=8.  Massive.  Lustre  dull;  color  between  sulphur  and  orpiment- 
yellow. 

Before  the  Blp,  behaves  like  oxide  of  lead. 

Minium. 

$  168.  PbO,Pb203.  G=4.6.  Pulverulent.  Color  vivid  red,  mixed  with 
yellow. 

Before  the  Blp,  behaves  like  oxide  of  lead. 

7 


74 


With  hydrochloric  acid,  evolves  chlorine  and  is  converted  into  chloride 
oflead.     With  nitric  acid,  becomes  brown. 
Galena. 

§  1G9.  PbS.  H=2.5— 2.75.  G=7.25— 7.7.  Color,  lead-gray  ;  of 
metallic  lustre.  Crystals  usually  affect  the  cubical  form,  and  possess 
very  perfect  cubic  cleavage. 

Heated  in  a  matrass,  sometimes  decrepitates  and  frequently  yields  a 
slight  white  sublimate.  Heated  in  an  open  glass  tube,  emits  sulphurous 
acid,  and,  on  the  heat  being  raised,  gives  a  white  sublimate  of  sulphate 
of  lead.  Heated  on  Ch,  affords  a  globule  of  pure  lead,  the  Ch  be- 
coming at  the  same  time  covered  with  sulphate  oflead  and  oxide  oflead. 
The  globule  of  metallic  lead  yields  generally  a  little  silver  on  cupella- 
tion.  The  presence  of  antimony  is  ascertained  as  shown  §  49.  Zinc, 
§113.  Iron,  |83. 

It  dissolves  with  some  difficulty  in  boiling  hydrochloric  acid,  with  evo- 
lution of  sulphuretted  hydrogen.  Very  dilute  nitric  acid  has  no  effect 
on  it,  but  by  a  stronger  acid  it  is  readily  dissolved  with  evolution  of 
nitrous  acid  vapors.  By  fuming  nitric  acid  and  aqua  regia  it  is  very 
violently  acted  upon,  being  converted  into  sulphate,  or  a  mixture  of  the 
sulphate  with  the  chloride. 
Bournonite. 

§  170.  3Cu2S,SbS3+2(3PbS,SbS3).  H=2.5— 3.  G=5.7— 5.9.  Occurs 
crystallized,  and  massive,  granular,  compact;  lustre  metallic;  color 
and  streak  steel-gray. 

In  a  matrass,  decrepitates  and  yields  with  strong  heat  a  dark-red  subli- 
mate. In  an  open  tube,  sulphurous  acid  is  evolved  and  abundant  anti- 
monial  fumes,  which  condense  partly  on  the  upper  and  partly  on  the 
lower  side  of  the  tube;  the  former  consist  of  antimonous  acid,  which  is 
volatile;  the  latter  is  not  volatile,  and  consists  of  a  mixture  of  antimo- 
nate  of  oxide  of  antimony  with  antimonate  of  lead.  On  Ch,  fuses 
readily  to  a  black  globule  and  deposits  a  Ct  of  antimonous  acid ;  with 
strong  heat  a  Ct  of  oxide  of  lead  is  obtained ;  the  remaining  globule, 
when  treated  with  Bx  in  OF1,  gives  the  reactions  of  copper,  and  the 
globule  assumes  the  appearance  of  metallic  copper. 


75 

Dissolves  readily  in  nitric  acid  to  a  blue  liquid,  leaving  a  residue  of 

antimonous  acid  and  sulphur.    Aqua  regia  leaves  a  residue  of  sulphur, 

chloride  of  lead,  and  antimonite  of  lead ;  the  solution  gives  a  precipitate 

with  water.     Ammonia  dissolves  a  portion  of  the  sulphide  of  antimony. 

The  following  ores  behave  before  the  Blp  in  a  very  similar  manner. 

G-eocronite.    PbS,  (SbS3,  AsS3)  +  4PbS. 

Dufrenoysite.    PbS,  AsS3  +  PbS. 

Boulangerite.    PbS,  SbS3  +  2PbS. 

Heteromorphite.    PbS,  SbS3  +  PbS. 

Jamesonite.    2  (PbS,  SbS3)  +  PbS. 

Plaglonite.    3  (PbS,  SbS3)  +  PbS. 

ZinJcenite.    PbS,  SbS3. 

Those  minerals  in  which  a  part  of  the  SbS3  is  substituted  by  AsS3, 
give  on  Ch  arsenical  vapors,  and  in  an  open  tube  a  crystalline  subli- 
mate. 

Cerasine  [Corneous  Lead]. 

§171.  PbCl  +  PbO.CO2.  H=2.75— 3.  G=6— 6.3.  Forms  crystals 
of  adamantine  lustre,  of  white,  gray,  or  yellow  color. 

In  a  matrass,  decrepitates  slightly  and  becomes  a  little  darker  yellow. 
On  Ch,  fuses  readily,  emits  acid  vapors,  becomes  reduced  to  metallic 
lead,  and  gives  a  white  Ct  of  chloride  of  lead  and  a  yellow  Ct  of  oxide. 

Dissolves  in  nitric  acid  with  effervescence. 
White  Lead  Ore  [Cerusite]. 

§  172.  PbO.  CO2.  H=3— 3.5.  G=6.4.  Occurs  granularly  massive, 
or  in  prismatic  needles,  or  compressed  plates.  Color  mostly  white,  yel- 
low, or  gray. 

When  heated  in  a  matrass,  decrepitates  and  turns  yellow ;  carbonic 
acid  is  given  out.  Heated  on  Ch  alone,  is  reduced  to  metallic  lead. 
Treated  with  fluxes,  dissolves  with  effervescence  and  gives  the  reactions 
of  pure  oxide  of  lead  (v.  Table  II,  12)  ;  dissolves  readily  and  with  effer- 
vescence in  dilute  nitric  acid  ;  with  hydrochloric  acid,  leaves  a  residue  of 
chloride  of  lead  ;  dissolves  in  a  solution  of  caustic  potassa. 


76 


Leadliillite. 

\  173.  PbO.  S034-3(PbO.C02).  H=2.5.  0=6.2—6.5.  Occurs  in 
transparent  crystals  of  pearly  or  resinous  lustre.  Color  white,  passing 
into  yellow,  green,  or  gray. 

On  Ch,  intumesces  slightly,  becomes  yellow,  but  white  again  on  cool- 
ing ;  with  greater  heat  easily  reduced  to  metallic  lead. 

Dissolves  in  nitric  acid  with  effervescence,  leaving  a  residue  of  sul- 
phate of  lead. 

Lead  Vitriol  [Anglesite]. 

§  174.  PbO.  SO3.  H=2.75— 3.  G=6.2.  It  often  occurs  in  small  octa- 
hedral crystals  with  many  facets,  but  more  frequently  in  laminar  masses  ; 
of  high  lustre. 

Heated  in  a  matrass,  decrepitates  and  usually  yields  a  little  water. 
Treated  on  Ch  in  OF1,  fuses  to  a  clear  bead,  which  on  cooling  turns 
milk-white ;  with  Sd  on  Ch,  affords  a  globule  of  metallic  lead ;  the  Sd  is 
absorbed  by  the  Ch  and  shows,  when  placed  on  silver-foil,  a  strong  sul- 
phur reaction.  With  the  fluxes,  gives  the  reactions  of  oxide  of  lead. 
Traces  of  iron  or  manganese  may  be  detected  by  Bx  or  Sd  as  shown 
$  83  and  90. 

It  dissolves  in  acids  only  with  great  difficulty ;  by  hydrochloric  acid  it 
is  partly  decomposed ;  the  pulverized  mineral  is  soluble  in  a  solution  of 
caustic  potassa. 

Phosphate  of  Lead  [Pyromorphite]. 

§175.  Essentially  PbCl  +  3(3PbO.[P05.As05J).  H  =  3.5  — 4  G  = 
6.5 — 7.  It  occurs  often  in  globular  masses  with  a  columnar  struc- 
ture, also  fibrous  and  granular.  Color  green,  yellow,  and  brown. 

Heated  in  a  matrass,  sometimes  decrepitates  and  yields,  with  con- 
tinued heat,  a  faint  white  and  volatile  sublimate  of  chloride  of  lead. 
Heated  in  the  platinum-pointed  pincers,  fuses  readily  and  colors  the  outer 
flame  blue ;  if  the  amount  of  phosphoric  acid  is  not  too  small  the  edges 
of  the  flame  will  appear  green.  With  SPh  and  oxide  of  copper,  gives 
the  reaction  for  chlorine,  §  65.  On  Ch  in  the  OF1,  fuses  to  a  globule, 
which  on  cooling  assumes  a  polyhedral  form  and  a  dark  color;  in 
the  RF1,  yields  a  Ct  of  oxide  of  lead,  and  the  globule,  on  cooling, 


assumes  dodecahedral  facets  of  pearly  lustre.  With  boracic  acid  and  iron 
wire,  gives  the  reaction  for  phosphoric  acid  (§  95).  With  Sd  on  Ch, 
affords  metallic  lead.  Some  varieties  contain  arsenic  acid,  which  is 
readily  detected  by  the  odor  when  treated  with  Sd  on  Ch  (§  54). 

Soluble  iu  nitric  acid,  and  solution  of  caustic  potassa. 

Plumbo-Resinite. 

\  176.  3PbO.  P05+6(A1203,3HO).  H=4— 4.5.  0=6.3—6.4.  In 
reniform  or  globular  masses,  with  a  columnar  structure;  also  compact 
massive.  Of  resinous  lustre;  color  usually  yellowish-brown  j  resembling 
gum-arabic  in  appearance. 

In  a  matrass,  decrepitates  and  gives  out  water.  In  the  forceps,  intu- 
mesces  and  colors  the  outer  flame  azure-blue.  On  Ch,  intumesces, 
becomes  white  and  opaque,  and  fuses  but  imperfectly,  depositing  a  faint 
white  Ct  of  chloride  of  lead.  In  small  quantities,  soluble  in  Bx  and 
SPh  to  clear  beads.  With  Sd  on  Ch,  minute  globules  of  metallic  lead 
are  obtained.  Treated  with  SoCo,  assumes  a  fine  blue  color. 

Soluble  in  nitric  acid. 

Red  Lead  Ore  [Crocoisite]. 

$177.  PbO.  CrO3.  H==2.5— 3.  G=5.9— 6.1.  Occurs  usually  in  bright 
hyacinth-red  crystals  of  adamantine  lustre. 

In  a  matrass,  decrepitates ;  the  crystals  are  broken  up  into  minute 
pieces  and  assume  a  darker  color.  On  Ch,  fuses  and  becomes  reduced 
with  detonation ;  a  Ct  of  oxide  of  lead  is  formed,  and  grayish-green  ses- 
quioxide  of, chromium  remains  with  the  metallic  globule.  With  Sd  on 
Ch,  affords  a  globule  of  metallic  lead.  With  Sd  on  platinum  foil,  fuses 
to  a  dark-yellow  mass,  which  becomes  green  in  RF1.  With  Bx  or  SPh 
in  OF1,  dissolved  ;  the  bead  appears  yellow  while  hot,  but  becomes  green 
on  cooling.  Fused  in  a  platinum  spoon  with  from  3  to  4  parts  of  bisul- 
phate  of  potassa,  gives  a  dark-violet  mass,  which  is  greenish-white  when 
cold. 

Dissolves  in  heated  hydrochloric  acid  to  a  green  liquid,  leaving  a  resi- 
due of  chloride  of  lead.  Dissolves  with  difficulty  in  nitric  acid  to  a  yel- 
lowish-red liquid.  A  solution  of  caustic  potassa  colors  it  brown,  and 
finally  dissolves  it  to  a  yellow  liquid. 


78 


Vauquelinite. 

1 178.  3CuO,2Cr03+2(3PbO,2Cr03).  H=2.5— 3.  G=5.5— 5.7.  Oc- 
curs usually  in  minute  crystals,  or  in.  reniform  or  granular  masses. 
Color  dark-green  to  brown,  sometimes  nearly  black. 

On  Ch, fuses  with  effervescence  toagray  submetallic  globule ;  where  the 
mass  is  in  contact  with  the  coal  small  globules  of  lead  make  their  ap- 
pearance ;  in  RF1  a  Ct  of  oxide  of  lead  is  formed.  With  Bx  or  SPh  in 
0  Fl,  clear  green  beads  are  obtained,  which  remain  green  on  cooling,  but 
which  on  application  of  the  RF1  become  red  and  opaque ;  this  reaction 
appears  most  distinctly  on  Ch  with  Sn.  With  Sd  on  platinum  wire  in 
OF1,  dissolves  to  a  transparent  green  bead,  which  on  cooling  becomes  yel- 
low and  opaque  ;  on  treating  the  bead  with  a  few  drops  of  water,  a  yellow 
solution  is  obtained,  in  which  the  presence  of  chromic  acid  may  be  proved 
as  described  $  68.  With  Sd  on  Ch,  is  completely  decomposed ;  on  treat- 
ing the  reduced  metals  with  boracic  acid  on  Ch  (v.  \  71 )  a  globule  of  me- 
tallic copper  is  obtained. 

Partly  soluble  in  nitric  acid  to  a  dark  green  liquid  ;  the  residue  is 
yellow. 

Wulfenite  [Yellow  Lead  Ore]. 

g  179.  PbO,  MoO3,  sometimes  with  a  little  CrO3.  H=2.75 — 3.  G=6.3 
— 6.9.  Crystallized  or  granularly  massive,  firmly  coherent.  Color  usu- 
ally wax-yellow,  passing  into  orange-yellow. 

In  a  matrass,  decrepitates  and  becomes  darker  while  hot.  On  Ch, 
fuses  and  is  partly  absorbed  by  the  coal,  while  metallic  lead*  and  a  Ct  of 
oxide  of  lead  are  deposited.  With  Bx  or  SPh  on  platinum  wire  gives 
the  reactions  of  molybdic  acid  (v.  Table  II,  15).  With  Sd  on  Ch,  affords 
a  globule  of  metallic  lead.  Fused  with  bisulphate  of  potassa  in  a  pla- 
tinum spoon,  a  yellowish  mass  is  obtained,  which  becomes  white  on  cool- 
ing; treated  with  distilled  water  and  a  piece  of  metallic  zinc  placed  into 
the  solution,  the  liquid  assumes  a  blue  color. 

Dissolves  in  concentrate  hydrochloric  acid  to  a  green  liquid,  leaving  a 
residue  of  chloride  of  lead.  The  pulverized  mineral  is  decomposed  on 
being  digested  with  nitric  acid ;  a  yellowish- white  residue  is  left,  which 
becomes  blue  when  exposed  to  air  in  thin  layers. 


79 


ORES  OF  MANGANESE. 

Pyrolusite  [Gray  Ore  of  Manganese]. 

§  180.  MnO2.  H=2— 2.5.  G=4.8.  Of  black  or  dark-gray  color  and 
little  lustre ;  powder  black  ;  sometimes  of  columnar  structure. 

In  a  matrass,  usually  yields  a  little  water ;  when  heated  to  redness, 
oxygen  is  evolved.  Alone  infusible,  but  turning  reddish-brown  when  the 
temperature  is  sufficiently  high.  Soluble  in  Bx  and  SPh  with  the  usual 
manganese-reactions;  gives  frequently  the  indications  of  iron. 

Soluble  in  hydrochloric  acid  with  disengagement  of  chlorine. 

Hausmannite  [Black  Manganese]. 

\  181.  MnO,  Mn203.  H=5— 5.5.  0=4.7.  Crystallized,  or  granular, 
particles  strongly  coherent.  Color  brownish-black  5  streak  chestnut- 
brown. 

Before  the  Blp,  and  to  hydrochloric  acid  behaves  like  the  preceding 
ore. 

Braunite. 

1 182.  Mn2  O3.  H=6— 6.5.  G=4.7 — 4.8.  Occurs  crystallized  or  mas- 
sive. Color  and  streak  dark  brownish-black. 

In  a  matrass,  does  not  give  any  water ;  behaves  otherwise  like  pyrolu- 
site.  Dissolves  in  hydrochloric  acid  with  disengagement  of  chlorine, 
leaving  sometimes  a  residue  of  silica. 

Psilomelane. 

§  183.  Composition  very  various,  essentially  Mn203  with  BaO  or  KO, 
and  HO.  H=5— 6.  0=3.7—4.3.  Massive.  Color  iron-black;  streak 
brownish-black,  shining. 

Before  the  Blp  and  to  solvents  it  behaves  like  pyrolusite. 
Wad  [Bog  Manganese]. 

1 184.  Essentially  MnO2,  MnO,  and  HO ;  contains  often  Fe203,- 
A1203,  BaO,  SiO3,  &c.  H=0.5— 6.  0=3—4.2.  Amorphous,  earthy  or 
compact,  of  a  dull  black  color. 

In  a  matrass,  yields  water  abundantly,  and  otherwise  behaves  like 
pyrolusite.  Some  varieties,  known  under  the  name  of  "Cupreous  Man- 


80 


ganese,"  when  treated  with  Sd  and  Bx  on  Ch,  afford  a  globule  of  metallic 
copper. 

Diallogite. 

§  185.  MnO,C02  when  pure,  sometimes  (MnO,  FeO,  CuO,  MgO), 
C0a.  H=3.5 — 4.5.  G=3.4— 3.6.  Occurs  crystallized,  or  in  globular 
masses  of  columnar  structure  ;  also  massive.  Color  shades  of  rose-red, 
brownish ;  streak  white. 

In  a  matrass,  some  varieties  give  a  little  water  and  decrepitate  vio- 
lently. Infusible.  Some  varieties,  when  heated  in  RF1,  become  mag- 
netic. Dissolves  in  fluxes  with  effervescence  and  gives  usually  the  reac- 
tion of  manganese  and  iron. 

The  pulverized  mineral  is  little  affected  by  hydrochloric  acid  in  the 
cold ;  on  heating  dissolves  with  effervescence. 

Franklinite. 

§186.  ZnO,Mn203+4  Fe203.  H=5.5— 6.5.  G=5.  Occurs  crystal- 
lized, and  massive.  Lustre  metallic ;  color  iron-black  ;  streak  dark  red- 
dish-brown 5  acts  slightly  on  the  magnet. 

Infusible.  Dissolves  in  Bx  and  SPh  with  manganese-reaction  ;  the 
Bx  bead,  when  treated  on  Ch  in  RF1  becomes  bottle-green.  With  Sd 
on  platinum  foil,  gives  manganese-reaction.  With  Sd  on  Ch,  gives  a 
faint  Ct  of  oxide  of  zinc,  which  becomes  more  distinct  on  addition  of  Bx. 

Dissolves  completely  in  heated  hydrochloric  acid  to  a  greenish-yellow 
liquid,  chlorine  being  evolved. 


ORES  OF  MERCURY. 

Native  Mercury. 

$  187.  Hg,  sometimes  containing  a  little  Ag.  G=13.5.  Metallic 
globules  of  a  tin-white  color. 

Heated  in  a  matrass,  is  converted  into  vapor,  which  condenses  in  the 
neck  of  the  matrass  to  small  metallic  globules. 

Dissolves  readily  in  nitric  acid. 


81 


Amalgam. 

I  188.  AgHg2  and  AgHg3.  H=3— 3.5.  0=10.5—14.  Occurs 
crystallized  and  massive.  Color  and  streak  silver-white;  opaque. 

In  a  matrass,  boils,  gives  a  sublimate  of  metallic  mercury,  and  leaves 
a  spongy  residue  of  silver,  which  on  Ch  fuses  readily  to  a  globule. 

Dissolves  readily  in  nitric  acid. 

Calomel  [Horn  Quicksilver]. 

\  189.  Hg2Cl.  H=l— 2.  G=6.48.  Occurs  usually  in  distinct  crys- 
tals or  crystalline  coats,  of  adamantine  lustre  and  yellowish-gray  color. 

In  a  matrass,  yields  a  white  sublimate  of  subchloride  of  mercury. 
Mixed  with  Sd  and  heated  in  a  matrass,  affords  globules  of  metallic  mer- 
cury. On  Ch,  completely  volatilized,  giving  a  white  Ct.  Shows  the 
chlorine-reaction  when  treated  as  described  §  65. 

Treated  with  boiling  hydrochloric  acid,  is  partly  dissolved  and  becomes 
gray.  Not  affected  by  nitric  acid,  dissolved  by  aqua  regia.  With  a 
solution  of  caustic  potassa,  becomes  black. 

Cinnabar. 

%  190.  HgS.  H=2— 2.5.  0=8.9.  Color  various  shades  of  red,  from 
cochineal-red  to  dark  brownish-red.  Powder  always  bright-red.  It 
occurs  in  very  small  flattened  crystals,  or  granularly  massive. 

Heated  in  a  matrass,  is  volatilized  and  condenses  to  a  black  sublimate, 
which  by  friction  assumes  a  red  color.  Mixed  with  Sd,  yields  on  heating 
globules  of  metallic  mercury.  In  an  open  glass  tube,  is  partially  decom- 
posed into  metallic  mercury  and  sulphurous  acid.  On  Ch  it  is,  when 
pure,  wholly  volatilized. 

Nitric  acid  and  hydrochloric  acid  have  no  visible  effect  on  it.  Aqua 
regia  dissolves  it,  part  of  the  sulphur  being  precipitated.  Insoluble  in 
caustic  potassa. 

ORES  OF  NICKEL. 
Copper  Nickel. 

§  191.  Ni2As  or  Ni2  (As.  Sb).  H=5— 5.5.  G=7.3— 7.6.  Usually 
massive ;  of  copper-red  color,  with  a  gray  tarnish,  and  metallic  lustre ; 
very  brittle. 


82 


In  a  matrass,  affords  a  very  slight  sublimate  of  arsenous  acid.  In  an 
open  glass  tube,  yields  a  copious  sublimate  of  arsenous  acid,  and  usually 
a  little  sulphurous  acid;  the  assay-piece  assumes  at  the  same  time  a  yel- 
lowish-green color  and  crumbles  to  powder.  On  Ch,  emits  arsenical 
fumes  and  fuses  to  a  white  and  brittle  globule  which,  when  treated  with 
Bx  in  RF1,  imparts  usually  to  the  flux  the  colors  of  iron  and  cobalt. 
Sometimes  a  faint  Ct  of  oxide  of  lead  is  deposited  on  the  Ch. 

Dissolves  almost  completely  in  concentrated  nitric  acid;  the  solution 
has  a  green  color;  on  cooling  arsenous  acid  separates.  Readily  dis- 
solved by  aqua  regia. 

Nickel  G-lance  [Gersdorffite], 

§  192.  (Ni,Fe)-f(S2,As).  H=5.5.  G=5.6— 6.9.  Of  silver-white 
or  steel-gray  color,  and  metallic  lustre. 

In  a  matrass,  decrepitates  violently  and  yields  a  yellowish-brown  subli- 
mate of  sulphide  of  arsenic.  In  an  open  glass  tube,  emits  arsenous  acid 
and  sulphurous  acid.  On  Ch,  fuses  with  emission  of  sulphur  and  arsenical 
fumes  to  a  globule  which,  when  treated  with  Bx  in  RF1,  gives  the  reac- 
tions of  iron  and  cobalt.  After  having  removed  these  two  metals,  the 
remaining  globule  exhibits  with  the  fluxes  the  reactions  of  pure  oxide  of 
nickel. 

Partly  dissolved  by  nitric  acid,  sulphur  and  arsenous  acid  being  pre- 
cipitated. 

Nickeliferous  Gray  Antimony  [Ullmannite]. 

§  193.  NiS2+Ni(Sb,As).  H=5— 5.5.  G=6.2— 6.5.  It  closely 
resembles  the  preceding  ore  in  its  physical  properties. 

In  a  matrass,  yields  a  slight  white  sublimate.  In  an  open  glass  tube, 
emits  copious  antimonial  fumes  and  sulphurous  acid.  On  Ch  in  RF1, 
fuses  to  a  globule,  and  coats  the  Ch  with  antimonous  acid ;  sometimes  the 
odor  of  arsenic  is  observable.  The  melting  globule,  when  treated  with 
Bx,  frequently  exhibits  the  reactions  of  iron  and  cobalt  besides  those  of 
nickel. 

It  is  violently  acted  upon  by  concentrated  nitric  acid,  sulphur,  anti- 
monous and  arsenous  acids  being  precipitated.  Aqua  regia  dissolves  it, 
excepting  the  sulphur,  to  a  green  liquid. 


83 


Capillary  Pyrites  [Millerite]. 

$  194.  NiS.  H=3— 3.5.  G=5.2 — 5.6.  Occurs  usually  in  delicate 
capillary  crystals  of  brass-yellow  color  and  metallic  lustre. 

In  an  open  glass  tube,  evolves  sulphurous  acid.  On  Ch,  fuses  with 
emission  of  sparks  to  a  metallic  globule  which  is  attracted  by  the  mag- 
net. The  calcined  mineral  gives  with  fluxes  the  indications  of  oxide  of 
nickel,  and  sometimes  also  those  of  oxide  of  cobalt. 

By  heated  concentrated  nitric  acid  it  is  but  little  affected,  but  its  color 
is  changed  to  gray.  By  aqua  regia  it  is  wholly  dissolved. 

Emerald  Nickel. 

\  195.  (NiO.C02+4HO)+2(NiO.HO).  H=3— 3.2.  G=2.5— 2.7. 
Usually  forms  incrustations  of  emerald-green  color,  and  vitreous  lustre. 

In  a  matrass,  loses  already  at  212°  a  considerable  amount  of  water, 
and  blackens.  In  Bx  and  SPh,  dissolves  with  effervescence,  exhibiting 
the  characteristic  nickel-reactions. 

Dissolves  easily  in  heated  dilute  hydrochloric  acid  with  effervescence. 

Annabergite  [Nickel  Green]. 

g  196.  3NiO.As05+8HO.  Soft.  In  capillary  crystals,  also  massive 
and  disseminated.  Color  fine  apple-green. 

In  a  matrass,  yields  water  and  darkens  in  color.  In  the  forceps,  fuses 
and  colors  the  outer  flame  light-blue.  On  Ch  in  RF1,  fuses  with  emis- 
sion of  arsenical  vapor  to  a  blackish-gray  globule  ;  when  treated  with  Bx 
the  globule  gives  the  reactions  of  nickel,  sometimes  also  those  of  iron 
and  cobalt. 

Soluble  in  acids. 

ORES  OP  SILVER. 

Native  Silver. 

$  197.  Pure  silver,  associated  with  gold,  copper,  arsenic,  iron,  and  other 
metals.  H=2.5— 3.  G=10— 11.  Color  silver-white  j  lustre  metallic  ; 
ductile  and  malleable.  Occurs  usually  in  twisted  filaments,  or  arbores- 
cent ;  sometimes  in  plates  or  massive. 


84 


On  Ch,  fuses  easily  to  a  globule,  which  assumes  a  bright  surface,  and 
shows  after  cooling  a  silver-white  color.  Foreign  metals  are  detected  by 
the  methods  given  \\  103-105. 

It  dissolves  in  nitric  acid. 
Antimonial  Silver  [Discrasite]. 

1 198.  Ag6Sb  and  Ag4Sb.  H=3.5— 4.  G=9.4— 9.8.  Occurs  crys- 
tallized or  massive,  granular.  Lustre  metallic ;  color  and  streak  silver- 
white. 

On  Ch,  fuses  readily  to  a  gray  non-ductile  globule  and  coats  the  Ch 
with  oxide  of  antimony ;  with  continued  heat  the  globule  assumes  the 
appearance  of  pure  silver,  and  the  Ct  becomes  reddish. 

Dissolves  in  nitric  acid,  leaving  a  residue  of  oxide  of  antimony. 

Horn  Silver  [Kerargyrite]. 

§  199.  Ag  Cl.  H=l— 1.5.  G=5.5.  Remarkable  for  its  pearl-gray 
or  greenish  color,  its  semi-transparency,  resinous  lustre,  and  more  espe- 
cially for  its  softness,  which  is  so  great  as  to  allow  it  to  be  marked  by 
the  nail.  It  turns  brown  on  exposure  to  air.  When  rubbed  with  a 
moistened  plate  of  zinc  or  iron  the  latter  becomes  covered  with  a  coating 
of  silver. 

It  fuses  in  a  candle-flame.  On  Ch,  is  easily  reduced,  especially  when 
mixed  with  Sd.  Mixed  with  oxide  of  copper  and  heated  on  Ch  in  RF1, 
chloride  of  copper  is  formed,  which  colors  the  flame  azure-blue  (v.  §  65). 

Insoluble  in  water  and  nitric  acid.  Slowly  soluble  in  caustic  ammonia. 
Partially  decomposed  by  a  boiling  solution  of  caustic  potassa. 

Embolite  [Chloro-bromide  of  Silver]. 

§200.  2AgBr+3AgCl.  H=l— 1.5.  G=5.3— 5.4.  Crystallized  or 
massive.  Lustre  resinous  ;  color  various  shades  of  green. 

On  Ch,  fuses  readily,  evolves  pungent  vapors  of  bromine,  and  affords 
a  globule  of  metallic  silver.  With  Sd  on  Ch,  reduced  ;  on  dissolving  in 
water  the  alkaline  mass  which  has  passed  into  the  coal,  evaporating  the 
solution  to  dryness,  and  treating  the  residue  with  bisulphate  of  potassa 
as  described  $  63,  bromine-vapors  are  given  out.  Fused  with  oxide  of 
copper  on  Ch  in  RF1,  colors  the  outer  flame  greenish,  then  blue  (v.  §  65). 


85 


Bromyrite  [Bromic  Silver]. 

I  201.  AgBr.  H=l — 2.  G=5.8 — 6.  Occurs  usually  in  small  con- 
cretions. Lustre  splendent ;  color  yellowish-green  or  green.  Sectile. 

Its  action  before  the  Blp  not  known ;  behaves  probably  like  the  pre- 
ceding. 

Only  slightly  affected  by  acids.  Dissolves  in  heated  concentrated 
ammonia. 

lodyrite  [lodic  Silver]. 

g  202.  Agl.  Soft.  G=5.5.  Occurs  crystallized  or  in  thin  plates  with 
a  lamellar  structure.  Color  citron-yellow  to  yellowish-green. 

On  Ch,  fuses  readily,  colors  the  flame  purple-red,  and  affords  a  globule 
of  silver. 

Silver  Glance. 

|  203.  AgS.  H=2— 2.5.  G=7.  Color  blackish  lead-gray:  lustre 
metallic.  It  is  easily  distinguished  from  other  minerals  of  the  same 
color  by  being  cut  by  a  knife  like  lead. 

On  Ch  in  OF1,  intumesces,  gives  out  sulphurous  acid,  and  finally  yields 
a  globule  of  metallic  silver. 

Soluble  in  dilute  nitric  acid,  leaving  a  residue  of  sulphur. 

Ruby  Silver  [Pyrargyrite.     Dark-red  Silver  Ore]. 

g204.  3AgS,  SbS3.  11=2—2.5.  G=5.Y— 5,9.  Color  dark  red  to 
black,  giving  a  cochineal-red  powder.  Crystallizes  in  hexagonal  prisms. 

In  a  matrass,  fuses  very  readily  and  yields  with  continued  heat  a  subli- 
mate of  tersulphide  of  antimony.  In  an  open  glass  tube  gives  antimonial 
fumes  and  sulphurous  acid.  On  Ch,  fuses  readily  and  deposits  a  Ct  of 
antimonous  acid,  being  converted  into  sulphide  of  silver;  if  for  a  long 
time  exposed  to  the  OF1  or,  when  mixed  with  Sd,  to  the  RF1,  affords  a 
globule  of  metallic  silver. 

Part  of  the  SbS3  is  sometimes  substituted  by  AsS3 ;  it  then  gives  out 
arsenical  fumes  when  mixed  with  Sd  and  heated  in  the  R  Fl  on  Ch. 

The  pulverized  mineral,  when  heated  with  nitric  acid,  turns  black  and 
is  ultimately  dissolved,  leaving  a  residue  of  sulphur  and  antimonous  acid. 

8 


86 


Caustic  potassa  also  blackens  it  and  effects  partial  solution,  from  which 
acids  precipitates  tersulphide  of  antimony. 
Proustite  [Light-red  Silver  Ore]. 

1  205.  3AgS,  AsS3.  H=2— 2.5.  G=5.4— 5.5.    Very  much  resembles 
the  dark-red  silver  ore,  but  is  of\a  somewhat  lighter  color. 

Before  the  Blp  and  to  solvents,  behaves  like  the  preceding,  excepting 
it  gives  off  arsenical  fumes  instead  of  antimonous  acid.  The  solution 
in  caustic  potassa  deposits  a  yellow  precipitate  when  neutralized  with 
acids. 

Brittle  Silver  Ore  [Stephanite]. 

2  206.  6  AgS,  SbS3.  11=2—2.5.  G=6.2.  Of  metallic  lustre  and  iron- 
black  color  |  it  is  very  brittle  and  fragile,  and  its  powder  black. 

In  a  matrass,  decrepitates,  then  fuses  and  ultimately  yields  a  faint 
sublimate  of  tersulphide  of  antimony.  On  Ch,  fuses  very  readily  and 
coats  the  Ch  with  antimonous  acid.  If  the  blast  with  the  0  Fl  is  kept 
up  for  a  sufficient  time,  the  Ct  assumes  a  red  color  and  a  globule  of  me- 
tallic silver  is  obtained.  Contains  frequently  copper  and  iron,  which  may 
be  detected  by  the  process  described  §  71.  If  arsenic  is  present  it  gives 
in  the  open  tube  a  crystalline  sublimate  of  arsenous  acid. 

In  dilute  heated  nitric  acid  it  dissolves,  excepting  the  sulphur  and 
antimonous  acid ;  the  solution  becomes  milky  on  addition  of  water. 
Partially  dissolved  by  a  boiling  solution  of  caustic  potassa. 

Polybasite. 

I  207.  9  (Cu2S,  AgS)  (SbS3,  AsS3).  H=2— 3.  G=6.2.  Occurs  usually 
in  short  tabular  prisms,  or  massive.  Lustre  metallic;  color  and  streak 
iron-black. 

In  a  matrass,  fuses  very  readily,  but  gives  nothing  volatile.  In  an 
open  tube,  gives  sulphurous  acid  and  antimonial  fumes ;  the  sublimate 
contains  sometimes  crystals  of  arsenous  acid.  On  Ch,  gives  a  Ct  of 
oxide  of  antimony ;  with  continued  heat,  gives  a  bright  metallic  globule, 
which,  on  cooling,  becomes  black  on  its  surface  ;  sometimes  a  faint  Ct 
of  oxide  of  zinc  is  deposited ;  the  metallic  globule  affords  with  fluxes  the 
reaction  of  silver  and  copper. 

With  acids  behaves  like  honrnonite. 


87 


Stromeyerite  [Argentiferous  Sulphide  of  Copper], 

\  208.  Cu2S.  +  AgS.  H=2.5— 3.  G=6.2— G.3.  Occurs  usually  in 
small  compact  masses.  Lustre  metallic  ;  color  dark  steel-gray. 

In  a  matrass,  fuses  easily  and  gives  sometimes  a  little  sulphur.  In  an 
open  tube,  fuses  to  a  globule  and  gives  sulphurous  acid.  On  Ch,  fuses 
to  a  gray  metallic  globule  which  is  a  little  malleable;  with  fluxes  the 
globule  gives  the  reactions  of  copper,  sometimes  also  those  of  iron  ;  on 
a  cupel  with  lead  affords  a  globule  of  silver. 

Dissolves  in  nitric  acid,  leaving  a  residue  of  sulphur. 

ORES  OF  Tix. 
Tin  Ore  [Cassiterite]. 

§209.  SnO2.  H=6— 7.  0=6.3—7.1.  It  occurs  crystallized  in  square 
prisms  terminated  by  more  or  less  complicated  pyramids ;  re-entrant 
angles  are  so  frequent  that  they  are  to  a  certain  extent  characteristic ; 
also  massive,  and  in  small  mammillated  masses  of  fibrous  texture,  hence 
called  "wood  tin."  Color  very  various,  but  usually  brown  or  black.  The 
crystals  commonly  possess  a  very  brilliant  lustre. 

Infusible  in  the  forceps ;  the  behavior  before  the  Blp  is  that  of  pure 
oxide  of  tin  (v.  Table  II,  22),  excepting  of  its  sometimes  imparting  to 
the  Bx  bead  a  slight  yellowish  tinge,  owing  to  the  presence  of  iron,  and 
exhibiting  the  reaction  for  manganese  when  fused  with  soda  and  nitre  on 
platinum-foil. 

Insoluble  in  acids.     Fused  with  caustic  potassa,  yields  a  mass  which 
is  mostly  soluble  in  water. 
Tin  Pyrites. 

§210.  2Cu2S}SnS2+2(FeS,ZnS),  SnS2.  H=4.  0=4.3—4.5.  Of 
steel-gray  or  iron-black  color,  and  metallic  lustre.  Occurs  usually 
massive,  granular,  and  disseminated. 

In  an  open  glass  tube,  yields  sulphurous  acid  and  oxide  of  tin,  which 
collects  close  to  the  assay-piece  and  which  cannot  be  volatilized  by  heat. 
On  Ch  in  RF1,  fuses  to  a  black  scoriaceous  globule;  in  OF1,  gives  out 
sulphurous  acid  and  becomes  covered  with  oxide  of  tin.  When  well 


88 


calcined  by  the  alternate  application  of  OF1  and  RF1,  gives  with  Bx  the 
indications  of  Fe  and  Cu.  With  Sd  and  Bx,  yields  a  globule  of  impure 
copper. 

Decomposed  by  nitric  acid  ;  a  blue  solution  is  obtained,  and  a  mixture 
of  sulphur  and  oxide  of  tin  remains  undissolved. 


ORES  OF  ZINC. 

Red  Zinc  Ore  [Zincite]. 

§211.  ZnO,  containing  some  Mn203.  H=4— 4.5.  G=5.4— 5.5.  Of 
a  deep-red  color  and  high  lustre  ;  of  distinctly  foliated  structure. 

Infusible  alone.  Dissolved  by  Bx  in  OF1  with  manganese  reaction. 
With  Sd  on  Ch,  deposits  a  copious  Ct  of  oxide  of  zinc. 

Soluble  in  nitric  acid  without  effervescence  j  in  hydrochloric  acid  with 
evolution  of  chlorine. 

Blende. 

§212.  ZnS.  H=3.5— 4.  0=3.9—4.2.  Of  very  variable  color,  from 
yellow  to  black  ;  of  resinous  lustre  and  lamellar  aspect,  distinctly  cleava- 
ble.  It  occurs  often  crystallized  in  rhomboidal  dodecahedrons.  The 
powder  is  always  light  colored,  white  or  grayish,  and  dull. 

In  a  matrass,  sometimes  decrepitates  violently,  but  gives  nothing  vola- 
tile ;  its  color  also  remains  unchanged,  excepting  the  green  varieties, 
which  become  yellow.  Strongly  heated  in  an  open  glass  tube,  sulphur- 
ous acid  is  evolved,  and  the  color  of  the  calcined  assay  is  white,  yellow- 
ish, or  brownish,  according  to  the  amount  of  FeS  which  it  contains. 
Alone,  infusible  or  only  rounded  at  the  thinnest  edges.  On  Ch  in  RF1 
a  feeble  dark  Ct  of  oxide  of  cadmium  is  usually  obtained,  which  is  soon 
followed  by  a  pure  zinc-Ct.  With  Sd  on  Ch,  is  easily  reduced,  and  the 
characteristic  zinc-flame  may  frequently  be  observed.  Iron  is  readily 
detected  by  calcining  the  mineral  in  the  OF1  and  treating  the  residue 
with  Bx. 

The  pulverized  mineral  dissolves  in  nitric  acid,  leaving  a  residue  of 
sulphur. 


89 


tSmithsonite  [Calamine]. 

§213.  ZnO.CO2.  H=5.  G=4— 4.5.  It  is  found  crystallized  in 
forms  derived  from  the  rhomboid.  Of  vitreous  lustre,  and  white,  grayish, 
or  brownish  color;  semi-transparent  or  opaque.  Often  stalactitic  or 
mammillary. 

Heated  in  a  matrass,  loses  carbonic  acid  and,  if  pure,  appears  after 
cooling  enamel-white.  The  ZnO  is  often  to  a  large  extent  substituted 
by  FeO,  MnO,  CdO,  PbO,  MgO,  CaO  ;  it  then,  after  cooling,  frequently 
assumes  a  dark  color  and  gives  with  fluxes  the  indications  of  iron  and 
manganese.  Mixed  with  Sd  and  exposed  to  the  R  Fl,  it  is  decomposed 
and  oxide  of  zinc  deposited  on  the  Ch.  If  the  temperature  was  raised 
sufficiently  high,  a  zinc-flame  is  sometimes  observable.  The  Ct  is  at  first 
dark  yellow,  or  reddish  when  cadmium  is  present. 

It  readily  dissolves  in  acids  with  effervescence ;  also  in  caustic 
potassa. 

Calamine. 

§214.  3ZnO  +  SiO3  +  2HO  or  2(3ZnO.Si03)+3HO.  H=4.3— 5. 
G=3.1 — 3.9.  It  closely  resembles  in  its  physical  characters  the  pre- 
ceding ore.  It  is  electric  by  heat ;  the  smallest  fragment  heated  attracts 
light  substances. 

Infusible  in  the  forceps.  In  a  matrass,  yields  water  and  turns  milk-white. 
Bx  dissolves  it  to  a  transparent  glass,  which  cannot  be  made  opaque  by 
flaming.  It  dissolves  in  SPh  to  a  transparent  glass,  which  becomes 
opaque  on  cooling,  and  in  which,  when  highly  saturated,  clouds  of  silica 
are  observable,  while  hot.  With  Sd  on  Ch,  swells  and  affords  with  diffi- 
culty a  Ct  of  oxide  of  zinc.  With  SoCo,  assumes  a  green  color,  which, 
when  the  heat  is  raised,  passes  into  a  fine  light-blue  on  the  fused  edges. 

It  is  readily  decomposed  by  acids,  with  separation  of  gelatinous  silicic 
acid.  Partly  dissolved  by  caustic  potassa. 


8* 


90 

APPENDIX. 

FOSSIL  FUEL. 

Anthracite. 

\  215.  C,  with  a  small  percentage  of  SiO3,  A1203,  and  Fe203.  H=2 
— 2.5.  G=1.3 — 1.8.  Lustre  bright,  often  sub-metallic ;  color  iron-black, 
frequently  iridescent.  Fracture  conchoidal. 

In  a  matrass,  gives  usually  a  little  water,  but  no  empyreumatic  oil. 
Heated  on  platinum  foil  in  OF1,  is  slowly  consumed  without  flame,  leav- 
ing a  small  quantity  of  ash,  which  consists  of  SiO3,  A1208,  and  more  or 
less  Fe203.  Does  not  color  a  boiling  solution  of  caustic  potassa. 

Bituminous  Goal  [Common  Coal]. 

|  216.  C,  H,  0  in  variable  proportions;  the  bituminous  matter  con- 
tains from  76  to  90  per  cent,  of  carbon ;  the  earthy  impurities  consist 
principally  of  SiO3,  A1208,  and  CaO  ;  contains  frequently  a  small  amount 
of  N  and  FeS2.  Softer  than  anthracite,  G=1.2— 1.5.  Less  highly  lus- 
trous than  the  preceding,  and  of  a  more  purely  black  or  brownish-black 
color. 

In  a  matrass,  some  varieties  soften  and  cake  (caking  coal),  while 
others  are  entirely  infusible ;  all  varieties  are  decomposed,  evolve  com- 
bustible gases  and  empyreumatic  oils,  and  leave  a  residue  of  more  or  less 
metallic  lustre  (coke),  which  behaves  like  anthracite.  On  platinum  foil, 
burns  with  a  luminous  flame  and  emission  of  smoke,  leaving  an  earthy 
residue. 

Boiled  with  a  solution  of  caustic  potassa,  or  with  ether,  imparts  to  these 
solvents  no,  or  only  a  pale-yellow,  color. 

Brown  Coal. 

§217.  Composition  the  same  as  that  of  bituminous  coal,  but  the 
organic  constituents  contain  only  from  60  to  75  per  cent,  of  carbon.  In 
physical  proportion  bears  sometimes  a  close  resemblance  to  the  pre- 
ceding; some  varieties  show  distinctly  the  texture  of  wood  (lignite). 

In  a  matrass,  infusible,  but  some  varieties  soften ;  evolves  combusti- 


91 


ble  gases,  empyreumatic  oils,  water  of  acid  reaction,  and  a  peculiar  disa- 
greeable odor,  leaving  a  residue  which  consists  of  carbon  and  a  consi- 
derable amount  of  ash.  On  platinum  foil,  burns  with  a  smoky  flame 
and  emission  of  a  peculiar  odor. 

Boiled  with  a  solution  of  caustic  po.tassa,  colors  the  liquid  brown. 

Asphaltum. 

§  218.  C,  H,  0,  in  variable  proportions,  with  about  75  per  cent,  of 
carbon.  G=l — 1.2.  Of  black  or  brownish-black  color,  and  bituminous 
odor. 

Fuses  at  about  100°  C,  and  burns  with  a  bright  flame  and  emission  of 
a  thick  smoke,  leaving  little  ash,  which  consists  essentially  of  SiO3, 
A1203,  and  Fe203.  In  a  matrass,  gives  empyreumatic  oil,  some  ammo- 
niacal  water,  combustible  gases,  and  leaves  a  carbonaceous  residue. 

Treated  with  boiling  ether,  colors  the  solvent  wine-red  to  bjownish-red 
(distinction  from  bituminous  coal);  treated  with  a  boiling  solution  of 
caustic  potassa,  does  not  color  the  liquid,  or  imparts  at  the  most  a  pale- 
yellow  color  (distinction  from  brown-coal). 


FIFTH  CHAPTER. 


SYSTEMATIC  METHOD  FOR  THE  DISCRIMINATION  OF 
INORGANIC  COMPOUNDS. 

THE  careful  observer,  having  become  well  acquainted  with  the  reac- 
tions which  are  exhibited  by  the  metallic  oxides  and  other  simple  com- 
pounds, when  subjected  to  the  various  treatments  detailed  in  the  second 
chapter,  will  find  no  difficulty  in  ascertaining  the  nature  of  any  mineral 
substance  presented  to  him  for  analysis. 

If  the  reactions  are  not  quite  distinct,  owing  to  an  intermixture  with 
other  substances,  he  may  call  to  his  aid  the  processes  laid  down  in  the 
third  chapter,  which  will  enable  him,  in  most  cases,  to  detect  also  the 
nature  of  the  impurities.  But  in  order  to  attain  satisfactory  results  in 
this  way,  a  certain  familiarity  with  all  the  principal  tests  is  a  necessary 
condition  ;  this  once  acquired,  any  further  directions  are  quite  superfluous. 

Those,  however,  who  have  not  devoted  much  time  to  blowpipe  opera- 
tions, will  sometimes  experience  some  difficulties  in  drawing  the  correct 
conclusions  from  the  observed  phenomena,  a  difficulty  which  is  to  a  great 
extent  obviated  by  pursuing  the  course  given  below.  This  methodical 
course  has  the  advantage  of  giving  the  operator  the  answer  to  every  phe- 
nomenon which  he  observes,  and  thus  leading  him,  though  sometimes  by 
a  very  tortuous  path,  to  the  right  solution.  An  example  will  show  this 
more  clearly,  and  teach  at  the  same  time  the  use  of  the  table. 

Suppose  a  substance  be  given  for  analysis.  The  operator  commences 
with  No.  1.  The  substance  is  heated  in  RF1  on  Ch :  a  garlic  odor  is 
disengaged ;  proceed  to  No.  2.  Treated  with  Sd  on  Ch  does  not  give  a 
mass  which  exhibits  the  reaction  of  sulphur ;  proceed  to  No.  3.  The 


substance  shows  no  metallic  aspect;  proceed  to  No.  131,  thence  to  No. 
135.  It  is  not  wholly  volatilized,  nor  does  it  exhibit  the  reaction  of  sul- 
phur; proceed  to  No.  137.  Here  we  find  that  the  substance  must  either 
be  an  arsenite  or  an  arsenate  (which  of  the  two,  cannot  be  decided  by 
the  Blp  alone),  and  to  find  the  metal,  we  proceed  to  No.  102.  It  affords, 
after  calcination,  with  Sd  on  Ch  a  fusible  metallic  button  ;  proceed  to 
No.  103.  The  button  is  oxidable  (because  on  being  heated  in  OF1, 
becomes  covered  with  a  black  coating  of  oxide);  proceed  to  No.  105. 
The  button  is  red  and  malleable ;  the  metal  is  copper.  The  substance, 
therefore,  was  arsenite,  or  arsenate,  of  copper. 

The  chief  constituents  of  the  body  having  thus  been  ascertained,  the 
analyst  should  never  omit  to  test  the  correctness  of  the  result  by  the  pro- 
cesses laid  down  in  the  third  chapter.  In  the  example  given  above,  he 
should  verify  the  result  by  the  test  given  in  §  57  for  arsenous  acid,  and 
by  those  given  in  $$  71  and  74  for  copper.  If  we  wish  to  examine  the 
assay  also  for  the  presence  or  absence  of  some  accessory  constituents,  we 
must  always  have  recourse  to  the  methods  detailed  in  Chapter  III.  For 
example,  having  found  the  body  under  trial  to  consist  essentially  of  sul- 
phur and  lead,  and  it  appears  desirable  to  know,  whether  or  not  it  con- 
tains any  silver,  we  must  subject  it  to  the  treatment  described  $  103. 

On  Ch  (RF1)  with  or  without  Sd  disengages  a  garlic  odor,     .  2 

Not, 4 

{With  Sd  (RF1)  on  Ch  yields  a  scoriaceous  mass  which  exhib- 
its the  sulphur-reaction  ($  107),          .         .  SulpJiarsenide.  131 
Not, 3 

T  Metallic  aspect,      .......  Arsenide.  131 

Not, Arsenite  and  Arsenate.  131 

On  Ch  (OF1)  disengages  sulphurous  acid,  and  exhibits  the 

sulphur-reaction  (g  107),    .        .          Sulphur  Compound,  125 

Not, 5 

On  Ch  disengages  the  odor  of  rotten  horse-radish,  . 

Selenium  Compound.  136 

Not, 6 


H 


C  The  substance,  after  having  been  well  dried,  fuses  on  red-hot 

<  Ch, 7 

(.Not, ....  11 

(  Treated  as  indicated  §  65  imparts  to  the  flame  an  azure-blue 

\  or  green  color, g 

**Not> Nitrate.  102 

{The  color  is  azure-blue,          .......  9 

The  color  is  green, 10 

C  Treated   as   indicated   $  63  disengages  deep  yellow  vapors, 

Bromate.  102 

Chlorate.  102 

( Treated  as  indicated  $  63  disengages  deep  yellow  vapors, 

10  S Bromate.  102 

I  Violet  vapors, lodate.  102 

C  Treated  as  indicated  $  65  imparts  to  the  flame  an  azure-blue 

11s       or  green  color, .         .12 

vNot, 17 

f  Heated  in  a  matrass  with  bisulphate  of  potassa  and  a  little 
peroxide  of  manganese  disengages  violet  vapors, 

12  •{ Iodide  and  lodate.  102 

I  Deep  yellow  vapors,       .        .         .       Bromide  and  Bromate.  102 

I^Not, 13 

(  Treated  as  indicated  \  77  exhibits  the  fluorine-reaction, 

13  < Fluoride.     102 

vNot, ;,     .  .        .        .14 

(  Treated  as  indicated  §  65  imparts  to  the  flame  an  azure-blue 

14  <       color, 15 

t  A  green  color, 16 

C  Heated  with  Sd  on  Ch  gives  a  mass  which,  when  mixed  with 
bisulphate   of    potassa   and    black    oxide    of   manganese 

15  1       and  heated  in  a  closed  tube,  evolves  a  deep  yellow  gas, 

Bromide.     102 

Chloride  and  Chlorate.     1 02 


95 

{Heated  with  Sd  on  Ch  gives  a  mass  which,  when  mixed  with 
bisulphate   of  potassa   and   peroxide   of  manganese   and 
heated  in  a  closed  tube,  evolves  violet  vapors,     .      Iodide.     102 
Deep  yellow  vapors, Bromide.     102 

Effervesces  with  hydrochloric  acid,        .         .          Carbonate.     102 


fEHer 
'  1  Not, 


18 
(  When  finely  powdered  and  heated  with  hydrochloric  acid, 

18  "\  effervesces,  ......  Carbonate.  102 

(.Not, 19 

(  When  finely  powdered  and  heated  with  concentrated  hydro- 

19-\  chloric  acid,  gelatinizes, 30 

I  Not, 20 

(  Fused  with  Sd  on  Ch  yields  neither  a  metallic  globule  nor 

20<  aCt,  . 21 

I  Yields  a  metallic  globule  or  a  Ct, 22 

(  Treated  as  indicated  §  61  colors  the  flame  yellowish-green, 

21  <       ,    .    .    •    .    ; Borate.     102 

I  Not,      ...',.".' 23 

TThe  scoriaceous  mass  is  heated  in  a  platinum  spoon  with  a 
drop  of  concentrated  sulphuric  acid,  then  alcohol  poured 

22  \       on  it,  and  lighted.     The  flame  appears  yellowish-green, 

| Borate.     102 

I^Not,      .     .    .   $&$'$. 23 

(  Treated  as  indicated  $77  exhibits  the  fluorine-reaction, 

23s Fluoride.     102 

I  Not, 24 

{Heated  with  Sd  on  Ch  yields  a  button  of  fused  metal,    .         .       25 
Not, 27 

f  Heated  on  Ch  alone  behaves  as  indicated  §  96  ;  yields  with 

25  <       Sd  on  Ch  a  soft  globule,    .        .        .    Phosphate  of  Lead. 

I  Not, 26 

f  The  scoriaceous  mass  treated  with  boracic  acid,  as  indicated 

26  4      \  95,  exhibits  the  reaction  of  phosphoric  acid,     Phosphate.     102 

(Not, 28 


96 


C  Treated  as  indicated  $  95  exhibits  the  reaction  of  phosphoric 

27s       acid,          .         .       MMSOI^    &»;,       .        .         Phosphate.  102 

I  Not, ,.-.  jw  t  t,: •- ....  28 

f  With  Sd  on  Ch  yields  a  metallic  button  or  a  copious  Ct,         .  31 

8\Not, 29 

{Pulverized  and  fused  with  5  or  6  times  its  weight  of  Sd  in  a 
platinum  spoon,  yields  a  mass  which,  when  heated  with 
hydrochloric  acid,  gives  a  gelatinous  precipitate,         .        .       30 
Not,    ..       .*       ^        .         :         .         .         .       .*       ..    &.       31 
(  The  gelatinous  precipitate  placed,  while  still  moist,  on  a  blade 
30^       of  iron  or  zinc,  becomes  blue,    .         .         .  Tungstate.     139 

I  Not, 140 

f  Metallic  aspect, 32 

01    J 

(Not,      .        .       ..      *.      >.      •.      -.      -.      -.        .        .      57 
C  Yields  on  Ch  a  malleable  and  fusible  metallic  button,  which  is 

32  <       notoxidable, 33 

I  Not,        .        .     .  .     .  V     .............    36 

f  Yellow  button,         ..'..""...     .   ......        .34 

33  < 

1  \  White  button, 35 

(  With  Bx  on  platinum  wire  gives  a  bluish  glass, 

34  <         .        .        .        .        .         .        .        .     Gold  with  Copper. 

I  Not, Gold. 

C  With  Bx  on  platinum  wire  gives  a  bluish  glass, 
35 1 Silver  with  Copper. 

I  Not,        . .        Silver. 

f  With  Bx  on  platinum  wire  gives  a  glass  which  is  blue  in  both 
36  <       flames, Cobalt. 

iNot, 37 

{Gives  with  Bx  the  reactions  of  oxide  of  copper,       ...     38 
Not, 42 

Red  and  malleable  metallic  button,         .         .         .      Copper. 


{Deposits  on  Ch  a  Ct,  yellow  while  hot,  white  when  cold,  .         .     41 
Not.     A  yellowish,  brittle  alloy,       .         .         Copper  and  Tin. 


97 

f  Malleable,  yellow  or  reddish  alloy,  .        .       Copper  and  Zinc. 

41  •% 

(^  White,  malleable  alloy,    .         .         .         Copper,  Zinc,  Nickel. 

42  {Very  fusible  metallic  button, 43 

(  Deposits  on  Ch  a  Ct, 44 

43  <  No  Ct  deposited  on  Ch  j    exhibits  the  reactions  of  tin, 

I *,     .;       .         .         .Tin. 

White  Ct,  very  volatile,  .        .  • 45 


f  Whit 
\  Not, 


44 

46 

(  Yields  on  Ch  a  brittle  globule,  which  exhibits  the  antimony- 

45  \       reactions,    .......         Antimony. 

(.Not,        ........          Tellurium. 

(  Metallic  aspect,  or  powder  assuming  metallic  lustre  under  the 

46  "\       polishing  steel,    .........     47 

I  Not,        .        .        ..'."/.' 50 

(  Infusible  and  inoxidable,         ....          Platinum. 
\  Oxidable, 48 

With  Bx  in  OF1  an  amethyst-colored  glass,     .        Manganese. 


f  With 
I  Not, 


49 

After   having   been  oxidized,  exhibits  with  fluxes   the   iron- 
reactions,     ....         ....          Iron. 

49  •{ 

After  having  been  oxidized,  exhibits  with  fluxes  the  nickel- 
reactions,     .         .         .         ...         .         .      Nickel. 

Yields  with  Sd  on  Ch  in  RF1  a  tin  globule,     .    Oxide  of  Tin. 


(  YieL 
\Not, 


51 
(  With  Bx  on  platinum  wire  a  green  glass  in  both  flames; 

< Chromic  Iron. 

I  Not, 52 

Yields  with  Sd  on  platinum  foil  in  OF1  a  bluish-green  mass,    .     53 


f  Yiel 
\Not, 
C  Gives  with  Bx  or  SPh  on  platinum  wire  an  amethyst-colored 

53  \      bead, Oxide  of  Manganese. 

LNot.     Brown  powder,     .     Tung  state  of  Iron  and  Manganese. 


9 


98 

{With  S  Ph  on  platinum  wire  in  RF1  gives  a  glass  which,  on 
cooling,  becomes  brownish-red  and,  when  touched  with  tin, 
violet-red,    ......      Titaniferous  Iron. 
Not ;  exhibits  the  iron-reactions, 55 

{Heated  in  a  closed  glass  tube,  yields  water;  powder  yellow, 
Hydrate  of  Sesquioxide  of  Iron. 
Yields  no  water, 56 

f  Magnetic ;  powder  black,         ....  Magnetic  Iron. 
56  \ 

(Not;  powder  red,   .....       Peroxide  of  Iron. 

f  Affords  with  Sd  on  Ch  in  RF1  a  fusible  metallic  button,           .     58 
7  I  Not, 66 

button  is  malleable  and  inoxidable, 59 

58 


/The 
\  Oxi. 


Oxidable  button,     .........     60 

Yellow  button,         .         .        .         .         .         .  Oxide  of  Gold. 

9      White  button,          .....         Oxide  of  Silver. 

{Button  with  Ct,        .........     61 
' 
-Malleable  button  without  Ct,  .        ......     75 

The  Ct  is  white  and  very  volatile,   .         .  Oxide  of  Antimony. 

62 


( 
H 


(  The  Ct  is  yellow,  and  the  button  soft,      .....     63 

62  "\ 

(  The  button  is  brittle,       ........     65 

A  very  small    quantity    affords  with   Bx  or  SPh  in   OF1    a 

63  ~\      green  glass,          .....    Ckromate  of  Lead. 

Not,       ...........     64 

The  substance  is  yellow  or  reddish,          .    Protoxide  of  Lead. 

64  <  The  substance  is  red,      ......    Minium. 

The  substance  is  brown,         .        .         .    Deutoxide  of  Lead. 
f  Affords  with  Bx  or  SPh  in  OF1  a  green  bead, 

65  <  .         ...         .        Chromate  of  Bismutli. 

t  Not,        .......     Oxide  of  Bismuth. 

Treated  on  Ch  in  OF1  deposits  a  Ct,  or  vaporizes  completely,      67 


°  '  Not 70 

The  Ct  is  white,  and  very  volatile,  .         .   Oxide  of  Antimony. 


f  The 
\  Not, 


67  68 


99 

The  Ct  is  brown,   .....  Oxide  of  Cadmium. 


{The 
Not, 


69 

The  substance  is  red  or  yellow  and  affords,  when  heated  in  a 
closed  glass  tube,  metallic  mercury,    ..... 


69- 


Oxide  of  Mercury. 


The  substance  is  white,  becomes  yellow  on  heating,  and  on  cool- 
ing white  again,          .         .....         .  Oxide  of  Zinc. 

C  Affords  with  Bx  a  bead  which  is  blue  in  both  flames, 

70  < Oxide  of  Cobalt. 

I  Not, 71 

The  Bx  bead  is  green  in  both  flames, 72 

Not,       %V->'w  .A  >  .'•!&  .>«t^.*t 77 

Soluble  in  water,    ........          .73 


72 

Insoluble  in  water, 74 


;  The  substance  is  orange  red,  .         .       Bichromate  of  Potassa. 
73 


\  The  substance  is  yellow,         .    Chromate  of  Potassa  or  Soda. 
The  substance  is  of  semi-metallic  aspect  or  grayish-black,       . 

Chromic  Iron. 

The  substance  is  a  green  powder,    ..... 

.         .        .          Sesquioxide  of  Chromium. 

The  button  is  white, Oxide  of  Tin. 

The  button  is  red, 76 

T  The  substance  is  red  or  brown,       .         .  Suboxide  of  Copper. 
( 6  < 

{  The  substance  is  black,  .         .         .          Protoxide  of  Copper. 

fThe  bead  is  green  in  OF1,  and   becomes  reddish-brown  in 
77  <      RF1, -  .         .76 

I  Not, .         .78 

The  bead  is  amethyst-colored  in  OF1, 79 

Not,       .        .        ..--.•.•.<<..        .         .80 

f  Gives  off  water  when  heated  in  a  glass  tube,  .... 
7  9  "\     ••'"*•        .        .         .          Hydrated  Oxide  of  Manga nese. 

\  Not,       ......          Oxide  of  Manganese. 

Heated  alone  on  Ch  in  OF1  becomes  magnetic,      .        .         .55 
Not,       >     v.      • ;     si 


100 


C  Exhibits  with  SPh  on  platinum  wire  the  uranium  reactions, 
\  •        •         •         •         .     •    .     •    .    Oxide  of  Uranium. 


82 
J  Soluble  in  water,  exhibiting  alkaline  reaction,         .         .          .83 

I  Not, 91 

g3  J  Very  soluble, 84 

[  But  little  soluble,   »•...«.  *    * 88 

f  Heated  on  platinum  wire,  fuses  readily  and  vaporizes,    .         .     85 
\  Not, 87 

C  Heated  on  platinum  foil,  stains  it  dark  yellow,         .        Litliia. 
80  "\ 

(  Not, 86 

r  Heated  on  platinum  wire,  colors  the  flame  pale  violet,    . 
„„  J  .         .         .         .        .         .         .  Hydrate  of  Potassa. 

j  Reddish-yellow;  the  outer  flame  becomes  enlarged, 

L  .        .         .....        .        .      Hydrate  of  Soda. 

C  Moistened  with  a  drop  of  hydrochloric  acid,  and  heated  on  pla- 

87  -s       tinum  wire,  colors  the  flame  pale-green,       .        .     Baryta. 

V.  Purple, Strontia. 

(  Moistened  with  a  drop  of  hydrochloric  acid,  and  heated  on  pla- 

88  \      tinum  wire,  colors  the  flame  purple,    .         .         .     Strontia. 

I  Not, 89 

{Heated  with  SoCo  assumes  a  flesh-color,          .         .  Magnesia. 
Not,       .        . 00 

Heated  alone,  becomes  very  luminous,   .         .         .          Lime. 


{Heat< 
Not; 


colors  the  flame  pale-green,  ....      Baryta. 
C  Heated  with  SoCo,  assumes  a  fine  blue  color,         .  Alumina. 

92 


{Heated  with  SoCo,  assumes  a  flesh-color,       .           Magnesia. 
Not, 93 

Heated  with  SoCo,  assumes  a  green  color,     .   Oxide  of  Zinc. 

Not, 94 

f  Affords  with  SPh  in  OF1  a  colorless  glass,  which  in  RF1 
94  "\       becomes  blue,    .....         ....       95 

(.Not, 97 


101 


(  Heated  in  a  closed  glass  tube,  evolves  ammonia  and  becomes 
95  -\       blue  or  green,    ....     Tungstate  of  Ammonia. 

(.Not, •:<!*r'i  ....       96 

Tiingstic  Acid, 
of  Potassa  or  Soda. 

(  Exhibits  with  SPh  the  reactions  of        .         .  Nolybdic  Acid. 

JNot,      .   KVM^      ..  ^itekr-rfw-faw  ....       98 

(  Exhibits  with  SPh  the  reactions  of  pure         .     Titanic  Acid. 

\  Not, 99 

(  Affords  with  SPh  in  RF1  a  reddish-yellow  glass ;  the  inten- 
99  <       sity  of  the  color  increases  on  cooling,          .         .         .         .100 

(Not, 101 


f  On  Ch  alone,  infusible,  .         .         . 

96  \ 

(  Fusible,        ....    Tungstate  oj 


(  The  glass,  when  heated  on  Ch  with  tin,  becomes  violet,  . 
\  ....  Titanic  Acid,  containing  Iron, 

r  With  Sd  on  Ch  in  RF1,  affords  a  metallic  powder  attract- 
|  able  by  the  magnet,  .  .  .  Oxide  of  Nickel. 
I  Not:  affords  with  SPh  in  OF1  a  glass  which,  while  hot, 
V  is  red,  and  colorless  when  cold,  .  Oxide  of  Cerium. 


NITRATES,  CHLORATES,  BROMATES,  IODATES,  CARBONATES, 
PHOSPHATES,  BORATES,  CHLORIDES,  BROMIDES,  IODIDES, 
OXIDES,  HYDRATES. 

Affords  with  Sd  on  Ch  in  RF1  a  fusible  metallic  button,  .  103 

Not, 109 

The  button  is  malleable  and  inoxidable,  .  .  .  .104 
The  button  is  oxidable, 105 

(  The  button  is  yellow,        ....     Salt  of  Gold. 

\  The  button  is  white,      ,  . .       . .        .        .   Salt  of  Silver. 

{The  button  is  red  and  malleable,       .           Salt  of  Copper. 
Not, 106 

C  The  button  is  white  and  malleable  and  forms  no  Ct, 

106   <       VWUi* Salt  of  Tin. 

I  Not,        >v^    .        . 107 


102 


f  Forms  a  white  and  very  volatile  Ct,        Salt  of  Antimony. 

\  The  Ct  is  orange-yellow,   .......     108 

f  The  button  is  malleable,  .....       -.      Salt  of  Lead. 
108  -\ 

\  The  button  is  brittle,         .         .         .        Salt  of  Bismuth. 

(  Treated  with  Sd  on  Ch  in  RF1,  deposits  a  Ct,    .         .         .110 
\  Not,          ......         .         .         .         .112 

f  The  Ct  is  white  and  very  volatile,     .      Salt  of  Antimony. 
\  Not,     **$-       .........     Ill 

(  The  Ct  is  reddish-brown,  .      •-«      •-  .      Salt  of  Cadmium. 
Ill  •<    The  Ct  is  yellow  while  hot,  and  white  when  cold, 

I          ........     Salt  of  Zinc. 

{On  Ch  alone,  affords  a  gray  and  infusible  powder  which, 
under  the  polishing  steel,  assumes  metallic  lustre, 
.......      Salt  of  Platinum. 
Not,          .        .        .      *MMj.'       .....     113 

(  Heated  with  Sd  in  a  closed  glass  tube  affords  a  sublimate 
113^        of  mercury,    .....        Salt  of  Mercury. 

I  Not,          ..........     114 

f  Heated  with  Sd  in  a  closed  glass  tube  disengages  ammo- 
114<        nia,       ......      Salt  of  Ammonia. 

I  Not,         ..........     115 

(  Gives  with  Bx  or  SPh  beads  which  are  blue  in  both  flames, 
115  <  .......  Salt  of  Cobalt. 

I  Not,         .......... 

The  beads  are  green  in  both  flames,      Salt  of  Chromium. 


6  117 


(  The  bead  exhibits  the  reactions  produced  by  oxide  of  cop- 
117<       per,       .        .        .        .        .        .          Salt  of  Copper. 

I  Not,          ..........     118 

f  Affords  with  Sd  on  Ch  a  metallic  powder,  which  assumes 
118  -\        lustre  by  friction,  and  is  attracted  by  the  magnet,  .         .     119 
I  Not,  ..........     120 

j   Gives  with  Bx  in  RF1  a  bottle-green  glass,      Salt  of  Iron. 
\  Gives  with  Bx  in  RF1  a  grayish  glass,          Salt  of  Nickel. 


103 


C  Gives  with  Bx  in  OF1  an  amethyst-colored  bead, 

120< Salt  of  Manganese. 

I  Not, 121 

r  Infusible   mass,  which  assumes,  with  SoCo,  previous   to 

fusion,  a  fine  blue  color,        .         .        Salt  of  Alumina. 

|    A  flesh-color,    .       ,,      ...       ,,»        .       Salt  of  Magnesia. 

I  Not,        ..r  :    .*>iy.  ;«• 122 

(  The  watery  solution  gives  a  precipitate  on  addition  of  some 

122  <       Sd, 123 

I  Not,          . 124 

Heated  on  platinum  wire,  colors  the  flame  pale-green, 

Salt  of  Baryta. 

123  < 

Colors  the  flame  purple,    .         .         .         Salt  of  Strontia. 

Not;  but  becomes  very  luminous,     .        .      Salt  of  Lime. 
(  Heated  on  platinum  wire,  colors  the  flame  violet, 

124<       r-a*r* -•«••«* Salt  of  Potassa. 

v  Colors  the  flame  reddish-yellow,         .         .     Salt  of  Soda. 


j    Metallic  aspect ;  sulphides,        .        .         .         .         .         .126 

125 


SULPHUR  COMPOUNDS. 

\  Not, 127 

(  The  substance  is  calcined,  and  the  metal  detected  by  pro- 

126  <  8 

I       ceeding  as  indicated  above,  beginning  with  No.      .         .     102 

(  Sulphates,    hyposulphates,    sulphites,    hyposulphites,   sul- 

127  "S       phides  prepared  artificially  by  precipitation,  and  a  few 

v      native  sulphides , 128 

{Heated  with  hydrochloric  acid  disengages : 

Sulphuretted  hydrogen,     .        .        .        ,         .  Sulphide.  130 

Sulphurous  acid, 129 

Nothing,   ....         Sulphate  or  Hyposulphate.  130 
(  Hydrochloric  acid  produces  a  white  precipitate  of  sulphur, 

129<        H*4» Hyposulphite.  130 

v.  Not,       t^j? Sulphite.  130 


104 

130  «(   The  metal  is  detected  beginning  with  No.         ...     102 

ARSENIC  COMPOUNDS. 

(  Metallic  aspect, .        .132 

1  I  Not, 135 

(  Readily  and  completely  volatilized  on  Ch,          ..         .        .133 

132  "\ 

\  Not, .        .        .134 

f  Gives  a  white  and  very  volatile  Ct,  Arsenide  of  Antimony. 

133  -s 

(  Not,          ........     Arsenic. 

(  The  substance,  which  is  an  arsenide  or  sulpharsenide,  is 
134*\  thoroughly  calcined,  and  then  the  metal  detected  as  in- 

v.      dicated  above,  beginning  with  No 102 

(  Wholly  volatilized  on  Ch,  and  exhibiting  the  reactions  of 
135  <  sulphur, 136 

v  Not  wholly  volatilized,  or  exhibiting  no  sulphur-reaction,     137 

{The  substance  is  yellow.   ....  Orpiment. 

The  substance  is  red,        .....     jRealgar. 
The  substance  is  very  volatile,          .         .  Arsenous  Acid. 

Not :  arsenite  or  arsenate.     The  substance  is  well  calcined 
137  "S 

with  alternating  OF1   and  RF1,  and  the   metal   found 

beginning  with  No.        .         .         .         .  .         .     102 

SELENIUM  COMPOUNDS. 

(  Metallic  aspect, Selenide. 

138 -\    Not:  selenite  or  selenate;  the  substance  is  well  calcined, 

v      and  the  metal  detected,  beginning  with  No.  .         .        .102 


TUNGSTATES. 

(  With  Sd  on  platinum  wire  in  OF1  affords  a  greenish-blue 

139  <L     mass, Wolfram. 

I  Not, 140 


105 


(  Heated  with  Sd  in  a  closed  glass  tube,  evolves  ammonia,  . 

140^  * Tungstate  of  Ammonia. 

I  Not, 141 

Soluble,    ....    Tungstate  of  Potassa  or  Soda. 


Insoluble,         .        .          Tungstate  of  Lime,  Baryta,  &c. 


SILICATES. 

C  The  analogy  in  chemical  composition  and  properties,  and 

the  number  of  native  silicates,  make  it  impossible  to  dis- 

142  •{       criminate  them  by  a  few  simple  tests.*     The  base  or 

bases   may,   however,  in   many  cases  be  detected  by 

^      proceeding  as  indicated  above,  beginning  with  No.         .     102 

#  For  the  discrimination  of  the  native  silicates,  v.  Chapter  VI. 


SIXTH  CHAPTER. 


ON  THE   DISCRIMINATION  OF  MINERALS   BY  MEANS  OF 
THE  BLOWPIPE,  AIDED  BY  HUMID  ANALYSIS. 

BY  the  methods  given  in  the  preceding  chapters,  we  can  readily  detect 
the  constituents  of  most  inorganic  compounds,  whether  prepared  arti- 
ficially or  occurring  in  nature;  especially  if  heavy  metals  form  the  prin- 
cipal constituents.  But  these  methods  do  not  enable  us  to  discriminate 
the  different  native  silicates,  and  other  mineral  bodies,  which  consist 
essentially  of  such  substances  that  do  not  show  any  very  characteristic 
reactions  before  the  blowpipe,  as  ex.  gr.  the  alkaline  earths.  In  some 
cases  we  may  succeed  in  ascertaining  the  principal  ingredients  of  the 
substance  under  examination,  but  fail  in  establishing  the  mineral  spe- 
cies. To  attain  this  end  more  securely,  we  must  pursue  a  course,  com- 
posed of  an  examination  of  the  physical  properties  of  the  body  and  of 
blowpipe  operations,  aided  by  humid  analysis.  The  course  adopted  in 
this  "  Manual"  is  that  given  by  Franz  Von  Kobell,  as  laid  down  in  his 
"  Tafeln  zur  Bestimmung  der  Mineralien"  The  following  is  only  an 
extract,  slightly  modified,  from  this  treatise: 

The  minerals,  according  to  Von  Kobell's  system,  are  arranged  in  two 
large  groups,  the  first  embracing  those  possessing  metallic  lustre,  the 
second  those  devoid  of  metallic  lustre.  To  avoid  mistakes,  originating 
in  the  fact  that  some  minerals  occur  sometimes  with,  and  sometimes 
without,  metallic  lustre,  these  minerals  will  be  found  enumerated  in  both 
groups. 


107 


The  same  precaution  has  been  taken  in  regard  to  those  species  in  which 
the  degree  of  fusibility,  whether  below  or  above  5,  might  appear  doubt, 
ful.  The  degree  of  fusibility  is  to  be  judged  of  from  the  following  scale: 

1.  Gray  Antimony. — Fusible  in  coarse  splinters  in  the  flame  of  a 
candle. 

2.  Natrolite. — Fusible  in  fine  splinters  in  the  flame  of  a  candle. 

3.  Almandine  or  Iron-Garnet. — Easily  fusible  before  the  blowpipe. 

4.  Actinolite  (a  variety  of  hornblende). — Fusible  before  the  Blp  in 
coarse  splinters. 

5.  Orthoclase. — Fusible  before  the  Blp  in  fine  splinters. 

6.  Broncite. — Fusible  on  the  edges  in  very  fine  splinters. 

The  fusibility,  when  equal  to  that  of  actinolite,  is  designated  by  4; 
when  between  that  of  natrolite  and  almandine,  by  2,  5,  and  so  on. 

The  two  large  groups  are  divided  into  classes  according  to  the  fusi- 
bility; these  again  in  divisions,  &c.,  by  which  means  we  obtain  the  fol- 
lowing general  classification : 

GROUP  1.  MINERALS  POSSESSING  A  METALLIC  LUSTRE. 

CLASS    I.  Native  malleable  metals,  and  mercury. 
CLASS  II.  Fusibility  1 — 5,  or  readily  volatile. 

Division  1.  Give  a  strong  arsenical  odor  on  Ch. 

Division  2.  Give  on  Ch,  or  in  an  open  tube,  the  horse-radish  odor  of 
selenium. 

Division  3.  Give  in  an  open  tube  a  white  or  grayish  sublimate,  which 
is  fusible  into  colorless  drops,  indicative  of  tellurium. 

Division  4.  Give  antimonial  fumes  on  Ch. 

Division  5.  Give  with  Sd  on  Ch  a  sulphur-reaction,  but  do  not  give 
indications  as  above. 

Division  6.  Do  not  exhibit  the  properties  of  the  preceding  divisions. 
CLASS  III.  Infusible,  or  fusibility  above  5,  and  not  volatile. 

Division  1.  Give  with  Bx,  in  small  quantities,  the  manganese-reaction. 

Division  2.  Treated  on  Ch  in  R  Fl,  become  magnetic. 

Division  3.  Resembling  those  of  division  2. 


108 


GROUP  II.  MINERALS  NOT  POSSESSING  METALLIC  LUSTRE. 

CLASS    I.  Easily  volatile,  or  combustible. 

CLASS  II.  Fusibility  1 — 5,  not,  or  only  partially  volatile. 

Part  I.  Give  with  Sd  on  Ch  a  metallic  globule  or  magnetic  metallic 

mass. 

Division  1.  Give  with  Sd  a  globule  of  silver. 
Division  2.  Give  with  Sd  a  globule  of  lead. 

Division  3.  When  moistened  with  hydrochloric  acid,  color  the  flame 
blue,  and  give  with  nitric  acid  a  solution  which,  on 
addition  of  an  excess  of  ammonia,  assumes  an  azure-blue 
color. 

Section  1.  Give  on  Ch  a  strong  arsenical  odor. 
Section  2.  Give  no  arsenical  odor. 
Division  4.  Impart  to  the  Bx  bead  a  blue  color. 
Division  5.  When  fused  on  Ch  in  RF1,  give  a  black  or  gray  metallic 

magnetic  mass. 

Section  1.  Give  on  fusion  a  strong  arsenical  odor. 
Section  2.  Soluble  in  hydrochloric  acid  without  leaving  a  perceptible 

residue,  and  without  gelatinizing. 
Section  3.  With  hydrochloric  acid,  form  a  jelly,  or  are  decomposed 

with  separation  of  silica. 
Section  4.  But  little  affected  by  acids. 
Division  6.  Not  belonging  to  either  of  the  preceding  divisions. 

Part  II.  With  Sd  on  Ch,  give  no  metallic  globule,  or  magnetic  me- 
tallic mass. 

Division  1.  After  fusion  and  continued  heating  on  Ch  or  in  the  forceps, 
have  an  alkaline  reaction,  and  change  to  blue  the  color 
of  a  moistened  red  litmus-paper. 
Section  1.  Easily  and  completely  soluble  in  water. 
Section  2.  Insoluble  in  water,  or  soluble  with  difficulty. 
Division  2.  Soluble  in  hydrochloric  acid  without  leaving  a  perceptible 
residue,  some  also  soluble  in  water ;  not  gelatinizing. 


109 


Division  3.  Soluble  in  hydrochloric  acid,  forming  a  perfect  jelly. 
Section  1.  Giving  water  in  a  matrass. 
Section  2.  Giving  traces,  or  no  water  in  a  matrass. 
Division  4.  Soluble   in   hydrochloric  acid  with   separation  of  silica, 

without  forming  a  perfect  jelly. 
Section  1.  Giving  water  in  a  matrass. 
Section  2.  Giving  traces,  or  no  water  in  a  matrass. 
Division  5.  Little  affected  by  hydrochloric  acid  5  imparting  to  the  Bx 

bead  the  color  of  manganese. 

Division  6.  Not  belonging  to  either  of  the  preceding  divisions. 
CLASS  III.  Infusible,  or  fusibility  above  5. 

Division  1.  After  ignition  moistened  with  So  Co  and  again  ignited,  as- 
sume a  bright-blue  color. 
Section  1.  Giving  much  water  in  a  matrass. 
Section  2.  Giving  little  or  no  water  in  a  matrass. 
Division  2.  Moistened  with  So  Co  and  ignited,  assume  a  green  color. 
Division  3.  After  ignition  have  an  alkaline  reaction,  and  turn  into 

blue  the  color  of  a  moistened  red  litmus-paper. 

Division  4.  Completely  soluble,  or  nearly  so,  in  hydrochloric  or  nitric 
acid,  without  gelatinizing  or  leaving  a  perceptible  residue 
of  silica. 
Division  5.  With  hydrochloric  acid,  form  a  jelly  or  are  decomposed 

with  separation  of  silica. 
Section  1.  Giving  water  in  a  matrass. 
Section  2.  Giving  traces,  or  no  water  in  a  matrass. 
Division  6.  Not  belonging  to  either  of  the  preceding  divisions. 
Section  1.  Hardness  below  7. 
Section  2.  Hardness=7,  or  above. 


GROUP  I.   MINERALS  POSSESSING  A  METALLIC  LUSTRE. 

CLASS  I.  NATIVE  MALLEABLE  METALS,  AND  MERCURY. 
Native  silver,  see  $  197. 
10 


110 


Native  Gold  and  Electrum  (alloy  of  silver  and  gold); 

see  §  150. 

Native  Copper,  see  §  134. 
Native  Lead,  characterized  by  coating  on  charcoal  (see 

§23)  and  softness;  H=1.5. 
Native  Platinum,  see  §  152. 
Native  Palladium,  distinguished  from  the  preceding  by 

being  soluble  in  nitric  acid. 
Native  Iron,  see  $  154. 
Native  Mercury,  see  §  187. 

CLASS  II.  FUSIBILITY  1  TO  5,  OR  READILY  VOLATILE. 
Division  1.  Give  a  strong  arsenical  odor  on  charcoal. 
Native  Arsenic,  see  $  118. 
Dufrenoysite,  see  §  170  ;  Tennantite,  see  §  139;  Polyba- 

site,  see  §  207  ;  Domeykite,  see  §  140. 
Smaltine,  see  §  128  ;  Cobaltine,  see  §  129. 
Copper    Nickel,   see   §171;    Gersdorffite,    see    g!92; 

Chloanthite=NiAs,   resembles  the   preceding    two; 

distinguished  from  copper  nickel  by  its  tin-white  color, 

and  from  gersdorffite  by  not  giving  the  reactions  for 

sulphur. 

Arsenical  Pyrites,  see  §  161. 
Division  2.  Give  on  charcoal,  or  in  an  open  tube,  the  horse-radish  odor 

of  selenium. 
Selenide     of    mercury=HgSe2,     Onofrite=Hg  (S.Se) 

and  selenide  of  mercury  and  lead  (Selenquecksilber- 

blei)=3PbSe+HgSe,    yield    metallic    mercury    on 

being  heated  with  Sd  in  a  closed  glass  tube  (§  91) ; 

the  latter  yields  a  globule  of  metallic  lead  on  being 

heated  on  charcoal  with  Sd. 
Clausthalite=Pb  Se.     Color  lead-gray;  volatile  without 

previous  fusion,  depositing  first  a  slight  gray,  then  a 

white,  and  finally  a  greenish-yellow  coating ;  with  Sd 

yields  with  difficulty  globules  of  lead. 


Ill 


Naumannite=Ag  Se.  Color  iron-black ;  melts  readily 
and  yields  with  Bx  a  globule  of  pure  silver. 

Berzelianite=CusSe  and  EucairiteCu2Se+Ag  Se.  Color 
of  the  former  silver- white,  of  the  latter  lead-gray. 
Distinguished  from  the  other  minerals  of  this  division 
by  giving  copper-reactions. 

Division  3.  Give  in  an  open  tube  a  white  or  grayish  sublimate,  which, 
is  fusible  into  colorless  drops,  indicative  of  tellurium^ 
see  $11. 

The  assay-piece  used  for  this  experiment  ought  not  to 
be  very  small.  It  must  also  be  borne  in  mind  that 
the  minerals  of  this  division  frequently  evolve  an  odor 
of  selenium,  owing  to  a  small  percentage  of  selenium 
which  they  contain  as  adventitious  constituent. 

The  minerals  of  this  division  may  be  subdivided  accord- 
ing to  their  color. 

a.  Ores  of  tellurium  of  tin-white  or  silver-white  color. 
Native  Tellurium,  fuses  readily  and  is  volatile  without 

leaving  a  residue. 
Hessite=Ag  Te,  and  Altaite=Pb  Te  ;  both  soluble  in 

nitric  acid;  the  former  yields  with  Sd  on  Ch  a  globule 

of  metallic  silver. 
Some  varieties  of  sylvanite,  see  $  151. 

b.  Ores  of  tellurium  of  lead-gray  or  steel-gray  color. 
Tetradymite,  see  1 123. 

Sylvanite,  see  $  151. 

Nagy  agite=Pb,  Au,  Te,  S.  Color  blackish  lead-gray.  Dis- 
tinguished from  the  preceding  by  its  solution  in  nitric 
acid  giving  a  copious  precipitate  with  sulphuric  acid. 
Division  4.  Give  copious  antimonial  fumes  on  charcoal  (see  §  16). 

The  fumes  possess  sometimes  the  odor  of  sulphurous 
acid  or  arsenic. 

Native  Antimony,  distinguished  by  its  tin-white  color; 
Stibnite,  see  $  115  ;  Zinkenite,  see  g  170;  Jamesonite, 
see  i  170  ;  Bournonite,  see  g  170. 


112 


The  powdered  stibnite,  on  being  heated  with  hydrate 
of  potassa,  assumes  a  yellow  color,  while  the  latter 
three  minerals,  which  are  steel-gray,  do  not  change 
color.  Bournonite,  on  being  treated  with  nitric 
acid,  imparts  to  the  solution  a  sky-blue  color,  and 
gives  copper-reactions  on  being  treated  as  described 
in  \  71.  Zinkenite  and  jamesonite  are  converted  into 
white  powders  by  treatment  with  nitric  acid  without 
imparting  a  color  to  the  acid ;  they  are  distinguished 
by  their  hardness,  that  of  zinkenite  being=3.5,  that 
of  jamesonite=2.5. 

Closely  resembling  the  above  in  their  chemical  behavior 
are  the  following  rare  minerals :  Plumosite,  see  g  170; 
Boulangerite,  see  $  120  ;  Geokronite,  see  $  170;  Pla- 
gionite,  see  $  170;  Kilbrikenite ;  Steinmannite. 

Discrasite,  see  §  198 ;  Stephanite,  see  §  206 :  Polytelite=S, 
Sb,  Zn,  Fe,  Ag,  Cu  ;  some  varieties  of  Tetrahedrite, 
see  §  138  ;  Miargyrite=AgS,  SbS3.  Discrasite  does 
not  give  a  sulphur -reaction,  all  the  others  do.  Polytelite 
gives  a  copper-reaction  on  being  treated  as  described 
in  §  73.  Miargyrite,  streak  dark  cherry-red  ;  stepha- 
nite,  streak  black.  Miargyrite  and  stephanite,  hard- 
ness=2.5  ;  Polytelite,  hardness=3.5.  All  the  mine- 
rals of  this  subdivision  give  a  globule  of  silver  on 
being  treated  as  described  §  104  or  §  105. 

Wolfsbergite  (antimonial  copper) =Cu2S,  SbS3;  does  not 
give  a  globule  of  silver,  but  yields  a  globule  of  me- 
tallic copper  on  being  treated  with  Sd  on  charcoal. 

Ullmannite,  see  \  193;  Berthierite,  see  |11G;  Breit- 
hauptite=Ni  Sb.  All  yield  a  magnetic  globule  with 
continued  heat.  Breithauptite  is  distinguished  from 
the  other  two  by  not  giving  a  sulphur-reaction. 

Division  3.  Give  with  Sd  on  CU  a  sulphur-reaction,  but  do  not  give 
the  general  reactions  of  the  preceding  divisions. 


113 


Silver  Glance,  see  §  203. 

Galena,  see  §  169. 

Cinnabar,  see  \  90. 

Manganblende=MnS.  Color  iron-black,  streak  green. 
The  pulverized  mineral  evolves  sulphuretted  hydrogen 
with  hydrochloric  acid. 

Hauerite=MnS2.  Color  brownish-black,  streak  brown- 
ish-red. Yields  sulphur  on  being  heated  in  a  matrass. 

Copper  Glance,  see  \  137;  Stromeyerite,  see  g  208;  Tin 
Pyrites,  see  §  210  ;  Copper  Pyrites,  see  §  135  ;  Purple 
Copper,  see  g  136  ;  Cuban=Cu2S,  Fe2S3;  Wittichite= 
3Cu2S,  BiS3;  Aikinite  (acicular  bismuth)=3Cu2S, 
BiS3+2(3PbS,BiS3;)  Grunauite=BiS3+10Ni2S3;  Cu- 
proplumbite=Cu2S,  2PbS.  All  these  minerals  are 
partially  soluble  in  nitric  acid,  the  solution  possessing 
a  sky-blue  or  green  color;  on  addition  of  water  to  the 
concentrated  solution  a  white  precipitate  is  produced, 
if  the  mineral  under  examination  was  wittichite,  gru- 
nauite,  or  aikinite.  [To  distinguish  these  three,  add 
to  the  acid  solution  sulphuric  acid :  a  precipitate  indi- 
cates aikinite ;  wittichite  gives  the  copper-reaction  on 
being  treated  as  described  in  $  73,  grunauite  not.] 
Copper  pyrites  and  cuban  are  distinguished  from  the 
others  by  their  brass-yellow  color ;  purple  copper  is 
also  characterized  by  its  color.  To  distinguish  the 
remaining  four  minerals,  make  a  solution  in  nitric 
acid ;  add  sulphuric  acid :  a  precipitate  indicates 
cuproplumbite ;  if  no  precipitate  is  produced,  add 
hydrochloric  acid  :  a  precipitate  indicates  stromeyer- 
ite ;  to  distinguish  between  copper-glance  and  tin 
pyrites,  see  \  137  and  g210. 

Millerite,  see  §  194;  Linnaeite,  see  1 130;  Iron  Pyrites, 
see  §  158 ;  Marcasite,  see  §  159  ;  Sternbergite=S,  Ag, 
10* 


114 


Fe.  The  members  of  this  subdivision  fuse  to  globules 
which  are  attracted  by  the  magnet.  They  are  readily 
distinguished  by  the  characteristics  given  in  Chapter 
III.  Sternbergite,  by  the  treatment  described  in  $  104, 
yields  a  globule  of  silver.  Marcasite  and  iron  pyrites 
can  only  be  distinguished  by  their  crystalline  form. 

Bismuthine,  see  g  125. 
Division  6.  Do  not  exhibit  the  properties  of  the  preceding  divisions. 

Amalgam,  see  $  188. 

Native  Bismuth,  see  §  122. 

Hematite,  see  §  156. 

Magnetite,  see  \  157. 

Wolfram=MnO,FeO,W03.  Color  dark  grayish  or  brown- 
ish-black. Fusibility=3.  The  pulverized  mineral  on 
being  boiled  with  aqua  regia  assumes  gradually  a 
yellowish  color. 

Samarskite=Nb03,  FeO,  U203,  YO.  Color  velvet-black. 
Fusibility=4.  By  fusing  the  pulverized  mineral  with 
hydrate  of  potassa,  boiling  the  fused  mass  with  hydro- 
chloric acid,  filtering,  and  concentrating  the  solution 
by  boiling  with  addition  of  tin  foil :  the  liquid  as- 
sumes a  fine  blue  color  which  does  not  pass  into  red 
on  addition  of  water  (as  is  the  -case  with  compounds 
containing  titanium),  but  becomes  paler  and  gradu- 
ally disappears. 

Rhodonite,  dark  varieties=3MnO.Si03,  3HO.  Yields 
water  on  being  heated  in  a  matrass.  Soluble  in  hy- 
drochloric acid  with  separation  of  silica. 

Some  varieties  of  psilomelane,  see  §  183. 

Lievrite  and  Allanite,  some  varieties,  see  p.  121. 

Plattnerite=Pb02.  Color  iron-black  ;  easily  reduced  to 
metallic  lead. 

Red  Copper,  some  varieties,  see  §  142. 


115 


CLASS  III.  INFUSIBLE,  OR  FUSIBILITY  ABOVE  5. 

Division  1.  Give  with  borax,  in  small  quantities,  the  manganese  reac- 
tions. 

The  members  of  this  division  are  distinguished  from 
each  other  principally  by  their  physical  properties. 

Braunite,  see  §  182  ;  Hausmannite,  see  §  181 ;  Psilome- 
lane,  see  §  183 ;  Pyrolusite,  see  §  180 ;  Franklinite, 
some  varieties,  see  $  186  ;  Mauganite=Mn203,  HO. 
Color  steel-gray  to  iron-black ;  streak  dark  reddish- 
brown  ;  hardness  3 — 4 ;  yields  water  in  a  matrass. 
Division  2.  Heated  on  charcoal  in  reduction-flame,  become  magnetic. 

Hematite,  see  §  156. 

Franklinite,  see  $  186;  Magnetite,  see  §  157. 

Titaniferous  iron,  see  $  162  ;  Some  varieties  of  Rutil  and 
Arkansite   (see  below) ;   some  varieties  of  Limonite 
(|  155),  and  Blende  (§  212). 
Division  3.  Minerals  resembling  those  of  Division  2. 

Chromic  Iron,  see  §  127. 

Molybdenite— MoS2 ;  Graphite=C.  Both  very  soft,  hard- 
ness=1.5.  Molybdenite,  when  heated  in  the  forceps, 
colors  the  flame  greenish ;  and  gives  a  sulphur-reac- 
tion when  treated  as  described  in  $  107. 

Arkansite=Ti02;  Perofskite=CaO.Ti02.  Both  give 
the  reaction  for  titanium  as  described  §111.  Distin- 
guished by  crystalline  form. 

Iridosmine,  see  $  153. 

Tantalite  and  Columbite=MnO,  FeO,  TaO3,  NbO3,  WO3, 
SnO2;  Yttro-tantalite  =  3(CaO.YO.FeO),  (TaO3, 
WO3).  The  color  of  these  minerals  is  iron-black; 
yttro-tantalite  loses  its  color  before  the  Blp  and  be- 
comes yellowish  or  white,  that  of  the  others  remains 
unchanged.  Acids  affect  them  but  little.  Tantalite 
and  columbite  give  the  same  reaction  as  samarskite 
when  treated  with  hydrate  of  potassa,  &c.  (See  p.  114.) 


116 


Pitchblende.  Color  usually  velvet-black,  lustre  greasy  ; 
partially  soluble  in  nitric  acid  to  a  yellow  liquid ;  the 
solution  gives  a  sulphur-yellow  precipitate  with  am- 


monia. 


GROUP  II.  MINERALS  NOT  POSSESSING  METALLIC  LUSTRE. 

CLASS  I.  EASILY  VOLATILE  OR  COMBUSTIBLE. 

Native  Sulphur.    Completely  volatile,  burns  with  a  blue 

flame  and  emission  of  sulphurous  acid. 
Eealgar,  see  g  119 ;  Orpiment,  see  §  120. 
Arsenolite,  see  $  121. 

Red  Antimony,  see  2  117;  Valentinite=Sb03.  Color 
white ;  does  not  change  color  with  hydrate  of  potassa ; 
does  not  evolve  sulphuretted  hydrogen  with  hydro- 
chloric acid. 

Sal-ammoniac=NH4Cl ;  Mascagnine=NH3; S03+2  HO. 
Color  white ;  both  evolve  ammonia  with  hydrate  of 
potassa  ;  the  former  is  volatile  without  previous  fusion, 
the  latter  intumesces. 
Cinnabar,  see  §  190  j  Calomel,  see  g  189. 
CLASS  II.  FUSIBILITY  1 — 5 ;  NOT,  OR  ONLY  PARTIALLY,  VOLATILE. 

Part  I.  Give  with  carbonate  of  soda  on  charcoal  a  metallic  globule 

or  a  magnetic  metallic  mass. 
Division  1.  Give  with  carbonate  of  soda  a  globule  of  silver. 

Proustite,  see  §  205  j  Ruby  Silver,  see  \  204 ;  Xantho- 
cone— 3AgS,  AsS5-l-2(3Ags,  AsS3),  behaves  like  prou- 
stite,  from  which  is  distinguished  by  its  yellow  streak. 
Horn  Silver,  see  \  199 ;  lodyrite,  see  §  202. 
Selbite=AgO,  CO2,  dissolves  in  nitric  acid  with  effer- 
vescence. 
Division  2.  Give  with  carbonate  of  soda  a  globule  of  lead. 


117 


The  minerals  of  this  division  are  all  soluble  in  nitric 
acid  ;  the  solution  gives  a  copious  precipitate  with  sul- 
phuric acid. 

Mimetine  =  PbCl  +  3(3PbO,  AsO6)  ;  Hedyphane  = 
PbCl+3(3[PbO.CaO],  [As05.P05]).  The  former 
completely,  the  latter  partially  reduced  to  metallic  lead 
with  evolution  of  arsenical  fumes. 

Pyromorphite,  see  g  175. 

Minium,  see  §  168 ;  Crocoisite,  see  g  177  j  Melano- 
chroite  =  3PbO,  2Cr03.  Ara3oxene  =  VO3,  AsO5, 
PbO,  ZnO.  Crocoisite  and  melanochroite  give  the 
chromium-reaction  (|  67).  The  latter  three,  on  being 
boiled  with  hydrochloric  acid,  give  an  emerald-green 
solution  ;  on  adding  alcohol  to  the  liquid,  concentrat- 
ing by  heat,  pouring  off  from  the  residue,  and  then 
adding  water :  the  liquid  assumes  a  sky-blue  color  if 
the  mineral  was  araoxene. 

Linarite==PbO.S08+CuO.HO  is  characterized  by  its 
deep  azure-blue  color. 

Cerusite,  see  g  172;  Cerasine,  see  g  171  ;  Leadhillite, 
see  §  173;  Lanarkite=PbO.C02+PbO.S03.  All 
soluble  in  nitric  acid  with  effervescence;  leadhillite 
and  lanarkite  leave  an  insoluble  residue  of  sulphate  of 
lead.  The  solution  of  cerasine  gives  with  nitrate  of 
silver  a  precipitate  of  chloride  of  silver. 

Mendipite=PbCl  +  2PbO  ;  Matlockite=PbCl  -f  PbO. 
Dissolve  in  nitric  acid  without  effervescence  ;  the  solu- 
tion gives  a  precipitate  with  nitrate  of  silver. 

Anglesite,  see  \  174. 

Wulfenite,  see  §129. 

Scheeletine=PbO,  "WO3.  Color  yellow,  yellowish-brown, 
lustre  resinous.  Soluble  in  abundant  quantity  of  hy- 
drochloric acid,  leaving  a  yellowish-green  residue 
(WO3).  With  sulphuric  acid  the  pulverized  mineral 
assumes  a  bright  lemon-yellow  color. 


118 


Vauquelinite,  see  §  178  ;  Vanadinite=2  PbO,  VO3  with 
PbCl  +  2PbO.  Color  of  the  former  blackish-green, 
olive-green  5  of  the  latter  brown,  yellowish.  Both  im- 
part to  the  borax-bead  an  emerald-green  color.  Both 
are  soluble  in  nitric  acid ;  the  solution  of  vanadinite 
is  yellow  and  gives  a  precipitate  with  nitrate  of  silver. 
That  of  vauquelinite  not. 

Division  3.   When  moistened  with  hydrochloric  acid,  color  the  flame 
blue ;  and  give  with  nitric  acid  a  solution  whicJi,  on 
addition  of  an  excess  of  ammonia,  assumes  an  azure- 
blue  color. 
Section  1.    Give  on  charcoal  a  strong  arsenical  odor. 

Olivenite,  see  §  147. 

Tyrolite,  see  §  148  ;  Chalcophyllite  =  8CuO.  As05+ 
23HO.  Color  green.  Both  decrepitate  violently  and 
yield  much  water ;  chalcophyllite  dissolves  in  ammo- 
nia without  leaving  a  residue. 

Liroconite=As05,  PO5,  CuO,  A103,  HO.  Color  sky-blue. 
Does  not  decrepitate ;  loses  22  per  cent,  of  water  on 
ignition. 

Euchroite  =  4CuO.As05+7HO  ;    Erinite=5CuO.As05 
-J-2HO.     Color  of  both  emerald-green.      The  former 
loses  by  ignition  18 J  per  cent,  of  water,  the   latter 
only  5  per  cent. 
Section  2.  Do  not  give  an  arsenical  odor  on  charcoal. 

Atakamite,  see  §  141. 

Cyanosite,  see  §  145 ;  Brochantite=3  CuO.  S03+3  HO ; 
Covelline=CuS.  These  three  minerals  give  a  sul- 
phur-reaction (§107);  cyanosite  is  soluble  in  water, 
the  other  two  not.  Color  of  covelline  dark  indigo- 
blue,  of  brochantite  emerald-green. 

Red  Copper,  see  \  142  ;  Melaconite=CuO  ;  Tenorite= 
CuO.  The  color  of  the  latter  two  is  dark  steel-gray 
to  black.  All  three  dissolve  readily  in  acids  without 
effervescence  (except  impure  varieties  of  melaconite). 


119 


Malachite,  see  $  143 ;  Azurite,  see  §  144 ;  Mysorin= 
CuO.  CO2.  Color  blackish-brown  ;  does  not  yield 
water  in  a  matrass.  All  three  dissolve  readily  in 
acids  with  effervescence. 

Phosphocalcite,  see  §  146  ;  Libethenite=4CuO.  P05+ 
HO;  Ehlite=5CuO.P05+3HO;  Tagilite=4  CuO. 
P05+3HO.  Are  all  readily  soluble  in  nitric  acid 
without  effervescence;  the  (slightly  acid)  solution 
gives  a  precipitate  with  acetate  of  lead.  Phosphocal- 
cite loses  14  per  cent,  of  water  on  ignition,  the  others 
less  (from  7 — 10£).  Libethenite  is  dark  olive-green  ; 
ehlite  and  tagilite  emerald-green. 

Chalcolite=3CuO,P05+2(U203,  P05)+24  HO.  Color 
emerald-green.  Dissolves  in  nitric  acid  to  a  yellow- 
ish-green liquid ;  on  addition  of  ammonia  in  excess, 
a  bluish-green  precipitate  is  formed,  the  supernatant 
liquid  being  blue. 
Division  4.  Impart  to  tlie  borax  bead  a  blue  color. 

Erythrine,  see  g  131 ;  Annabergite,  see  §  196. 

Division  5.   When  fused  on  charcoal  in  reduction-flame,  give  a  black 
metallic  magnetic  mass. 

To  observe  well  the  magnetic  character  of  the  fused 
mineral,  it  is  advisable  to  expose  a  pretty  large  assay- 
piece  to  the  action  of  the  reduction-flame. 
Section  1.    Evolve  a  strong  arsenical  odor  on  being  fused. 

Scorodite,  see  §  166  5  Pitticite=Fe203,  As05+H0  j  Beu- 
dantite=3  FeO.  As05+3  Fe203, 2  As05+18  HO.  The 
pulverized  minerals  assume  with  hydrate  of  potassa  a 
reddish-brown  color.  Scorodite  and  beudantite  occur 
crystallized ;  pitticite  massive,  reniform. 

Arseniosiderite  =  5CaO,As08+3(2FeO,As06)+llHO. 
Color  yellowish-brown  ;  fibrous  ;  lustre  silky. 

Pyromeline=NiO,  SO3,  HO,  AsO6.     Partly  soluble  in 


120 


water ;  the  solution  assumes  a  blue  color  on  addition 
of  ammonia. 

Section  2.     Soluble  in  hydrochloric  acid  without  leaving  a  percep- 
tible residue,  and  without  gelatinizing. 

Green  Vitriol,  see  \  164;  Botryogen=3FeO,2S03-{- 
3(Fe203,2S03)  +  36HO.  Are  soluble  in  water; 
botryogen  leaves  an  ochreous  residue.  A  similar 
behavior  show  Copiapite=2Fez03, 5S03+18HO  (color 
yellow),  and  Coquimbite=Fe203,  3S03+9HO,  color 
white. 

Spathic  Iron,  see  g  163. 

Hureaulite  =  3(5  MnO,  2P05)  +  5FeO,  2P05  +  30HO  ; 
Triplite=4MnO.P05  +  4FeO.P05.  Fuse  readily; 
moistened  with  sulphuric  acid  give  the  phosphoric 
acid  reaction  ($  35) ;  with  borax  strong  manganese- 
reaction  ;  hureaulite  yields  much  water,  triplite  none 
or  very  little. 

Triphiline  =  3  LiO,  P05+6(3[FeO,  MnO],  PO5)  shows 
a  similar  behavior;  the  manganese-reaction  is  less 
decided.  On  dissolving  the  mineral  in  hydrochloric 
acid,  evaporating  the  solution  to  dryness,  adding  alco- 
hol, heating  the  alcohol  to  ebullition  and  burning  the 
vapor,  the  flame  assumes  a  purple  color. 

Vivianite,  see  §  165;  Anglarite=4  FeO.P05+4  HO  ; 
Dufrenite=2  Fe203.  P05+2i  HO ;  Cacoxene=2  FeO. 
POM-12HO.  Fuse  readily  and  behave  with  sulphuric 
acid  like  the  preceding ;  give  no  manganese-reaction. 
Yield  much  water  in  a  matrass:  cacoxene  33  per 
cent;  vivianite  28  percent.;  anglarite  16  per  cent.; 
dufrenite  8^  per  cent.  Color  of  anglarite  bluish-gray ; 
of  dufrenite  leek-green  •  of  cacoxene  ochre-yellow. 

Hematite,  see  §  156. 

Section  3.    With  hydrochloric  acid  form  a  jelly,  or  are  readily  de- 
composed with  separation  of  silica. 


Cronstedtite  =  S(FeO.MnO.MgO),  SiO3  +  Fe203,3HO. 
Color  black ;  streak  dark  leek-green ;  yields  water ; 
gelatinizes  with  hydrochloric  acid. 

Lievrite=:3(3[FeO,CaO],Si03)  +  2(Al203,Fe203),Si03  j 
Allanite=3(CeO,CaO),Si03+2([Fe203,AP03],Si03). 
Yield  no  water,  or  only  a  trace ;  gelatinize  with  hydro- 
chloric acid;  allanite  fuses  with  intumescence  to  a 
voluminous  brownish  or  blackish  glass  j  lievrite  intu- 
mesces  but  slightly,  decrepitates  and  fuses  to  an  iron- 
black  bead.  Hardness  of  allanite=G,  of  lievrite=5 — 6. 

Pyrosmalite  =  Fe2Cl3  +  Fe203, 6  HO  -f  4  ( [3  FeO,  2  SiO3] 
-f  [3  MnO,  2  SiO3] ).  Does  not  gelatinize  j  fusibility= 
2  ;  gives  the  chlorine-reaction  ($65). 

Allochroite[Hme-iron-garnet]==3CaO,Si03+Fe203,Si03. 
Gelatinizes  imperfectly;  fuses  readily;  distinguished 
from  the  preceding  by  absence  of  cleavage. 

Hisingerite=(3FeO,Fe203),Si08+xHO  ;  Xylotile  [a  va- 
riety of  serpentine].  Fuse  with  difficulty;  do  not 
gelatinize.  The  former  is  black,  amorphous;  the 
latter  brown,  fibrous,  woody.  Both  yield  water  in  a 
matrass. 

Some  impure  varieties  of  Limonite,  see  1 155. 
Section  4.  But  little  affected  by  acids. 

Crocidolite  =  3(NaO,MgO),  4Si03  -f  3  (3  FeO,  2Si03)  + 
xHO ;  Arfvedsonite=NaO,  Si03+3FeO,  2Si03.  Fusi- 
bility=1.7 — 2.  Color  of  crocidolite  lavender-blue  or 
leek-green,  fibrous,  yields  water  in  a  matrass;  arf- 
vedsonite  is  black  and  yields  no  water. 

[See  also  Hornblende  and  Tourmaline,  below,  some 
varieties  of  which  become  slightly  magnetic  after 
fusion.] 

Green  Earth  [a  variety  of  pyroxene].     Fusibility=3; 
color  celandine-green  ;  hardness=l  ;  earthy. 

Acmite=NaO.Si03+Fe203,  2Si03;    Hedenbergite    [a 
11 


black  pyroxene]=3Ca0.2Si03+3Fe0.2Si03.  Fusi- 
bility  of  the  forraer=2,  of  the  latter=2.6 ;  form  a  black 
lustrous  slag.  Both  are  cleavable. 

Almandine  [iron-garnet]  =3FeO.Si03+Al203.Si03.  Fu- 
sibility=3  ;  hardness=7 — 7.5.  Color  red,  reddish- 
brown.  Not  cleavable. 

Rhodonite,  some  varieties ;  see  below. 

Lepidolite,  some  varieties  ;  see  below. 
Division  6.  Not  belonging  to  either  of  tlie  preceding  divisions. 

Molybdine=Mo03.  Color  sulphur-yellow ;  earthy.  Gives 
with  the  fluxes  the  reactions  of  molybdic  acid.  Dis- 
solves readily  in  hydrochloric  acid ;  the  solution  is 
colorless,  but  turns  blue  on  being  stirred  with  an  iron 
spatula. 

Eulytine=2  BiO3,  3  Si03with  some  phosphate  and  fluor- 
ide of  iron.  Gelatinizes  with  hydrochloric  acid.  On 
charcoal  yields  a  globule  of  metallic  bismuth. 

Bismutite,  see  §  124. 

Part  II.  With  carbonate  of  soda  on  charcoal,  give  no  metallic  glo- 
bule or  magnetic  metallic  mass. 

Division  1.  After  fusion  and  continued  heating  on  charcoal  or  in  the 
forceps,  have  an  alkaline  reaction,  and  change  to  blue 
the  color  of  a  moistened  red  litmus-paper. 
Section  1.  Readily  and  completely  soluble  in  water. 

Nitre=KO.N05 ;  Nitratine=NaO.N05.  Deflagrate 
vividly  on  burning  coals.  Fused  on  platina  wire,  the 
former  colors  the  flames  bluish  with  a  red  tint ;  the 
latter  bright-yellow. 

Natron=NaO.C02+10HO ;  Trona=2Na0.3C02+4HO. 
The  watery  solution  has  an  alkaline  reaction,  and 
effervesces  on  addition  of  hydrochloric  acid. 

Glauber  Salt=NaO.  S03+10HO  ;  Thenardite=NaO. 
SO3;  Glaserite=KO.S03  j  Epsomite=MgO.S03+ 
7HO;  Potash  Alum=KO.S03+Al202.  3S03+24HO. 


123 


The  watery  solutions  of  these  minerals  give  a  co- 
pious precipitate  with  chloride  of  barium ;  the  solu- 
tion of  potash  alum  and  epsomite  are  precipitated  by 
carbonate  of  potassa  [distinguished  by  reaction  with 
solution  of  cobalt,  \  44]  j  the  concentrated  solution  of 
glaserite  gives  a  precipitate  with  bichloride  of  platina ; 
glauber  salt  yields  much  water,  thenardite  none. 

Common  Salt=NaCl.  The  watery  solution  gives  a 
copious  precipitate  with  nitrate  of  silver.  Gives  also 
the  reactions  for  chlorine  described  $$  65,  66. 

Borax=Na0.2BOM-10HO.     Gives    the    reaction    for 

boracic  acid,  g  60. 
Section  2.  Insoluble  in  water,  or  soluble  with  difficulty. 

Gay-Lussite=CaO.C02+NaO.C02+6HO;Whitherite= 
BaO.CO2.  Dissolve  in  dilute  hydrochloric  acid  with 
effervescence ;  the  former  yields  water,  the  latter  not. 

Anhydrite=CaO.S03;  Gypsum=CaO.S03+2HO  ;  Po- 
lyhalite=KO.S03+  MgO.S03+  2(CaO.S03)  +  2HO  j 
Glauberite=NaO.S03+CaO.S03.  Soluble  in  much 
hydrochloric  acid  5  in  the  solution  chloride  of  barium 
gives  a  precipitate.  Gypsum  yields  much  water,  poly- 
halite  little,  the  rest  none ;  anhydrite  is  distinguished 
by  superior  hardness=3.5  ;  polyhalite  is  distinguished 
from  glauberite  by  its  solution  giving  a  yellow  pre- 
cipitate with  bichloride  of  platina. 

Barytes=BaO.S03 ;  Celestine=SrO.S03.  Insoluble  in 
hydrochloric  acid ;  give  a  sulphur  reaction  when 
treated  as  described  §  107.  Celestine  colors  the  flame 
red,  \  34 ;  barytes  yellowish-green,  \  35. 

Fluor=CaF ;  Cryolite=3NaF+Al2F3 ;  Pharmacolite 
=2CaO.As05-f6HO.  Do  not  effervesce  with  acids, 
and  give  no  sulphur  reaction.  Pharmacolite  evolves 
arsenical  odor  on  charcoal ;  the  other  two  give  fluorine 
reaction,  §  76.  Fusibility  of  fluor=3,  of  cryolite=l. 


124 


Chiolite=3NaF+ 2 A12F3,  behaves  like  cryolite;  occurs 
only  massive  granular;  white  cryolite  is  distinctly 
crystalline  and  cleavable  in  3  directions. 

Division  2.  Soluble  in  hydrochloric  acid  without  leaving  a  perceptible 
residue;  some  also  soluble  in  water  ;  not  gelatinizing. 

Ammonia  Alum  =  NH4O.S03  +  A1203.  3S03+  24HO ; 
Goslarite=ZnO.S08+?HO.  Both  soluble  in  water  ; 
give  sulphur  reaction,  §  107.  Heated  on  charcoal  and 
treated  with  solution  of  cobalt,  the  former  assumes  a 
blue,  the  latter  a  green,  color,  \\  44,  45. 

Sassolin=B03j3HO  ;  Boracite=3MgO,4B03;  Hydro- 
boracite=3(CaO.MgO),4B03+18HO.  Give  the  bo- 
racic  acid  reaction,  \  GO.  Sassoline  is  soluble  in  al- 
cohol, the  others  not;  boracite  yields  no  water,  while 
the  others  do. 

Manganblende  and  Hauerite  give  strong  manganese 
reaction;  see  p.  113. 

\Yagnerite=MgF+3MgO.P05 ;  Apatite=3(3CaO.P05) 
+Ca(Cl,F).  Moistened  with  sulphuric  acid,  impart  a 
pale  bluish-green  color  to  the  flame.  Fusibility  of 
wagnerite=3 — 3.5  (with  intumescence) ;  of  apatite=5 
(without  intumescence) ;  wagnerite  is  soluble  in  dilute 
sulphuric  acid ;  apatite  not. 

Amblygonite=LiO,  NaO,  A?03,  PO5,  F.  Fusibility=2  ; 
hardness=6.  With  difficulty  soluble  in  concentrated 
sulphuric  or  hydrochloric  acid. 

Uranite=3CaO.P05+2(3U203.  P05)+24HO.  Fuses 
readily,  yields  water,  and  gives  with  fluxes  the  reactions 
of  sesquioxide  of  uranium.  See  Table  II. 

Division  3.  Soluble  in  hydrochloric  acid,  forming  a  perfect  jelly. 
Section  1.  Give  water  in  a  matrass. 

Datholite=3(CaO.B03)  +  3Ca0.4Si03  +  3HO.  Yields 
but  little  water,  and  gives  the  boracic  acid  reac- 
tion, §  60. 


125 


Natrolite=NaO.Si03+AP03.Si03  +  2110.  Fusibility 
=2,  does  not  intumesce  ;  hardness=5 — 5.5. 

Scolecite=CaO.Si03+Al203.  Si03+3HO ;  Laumontite 
=3Ca0.2Si03+3(Al203. 2Si03)+12HO.  Scolecite, 
on  being  heated,  curls  up  like  a  worm  and  finally 
melts  to  a  bulky,  shining  slag,  which  in  the  inner 
flame  becomes  a  vesicular  slightly  translucent  bead ; 
hardness=5.5.  Laumontite  intumesces  and  fuses  to 
a  white  translucent  enamel ;  hardness=3. 

Nearly  related  to  scolecite  and  showing  a  similar  be- 
havior, are  Mesolite  and  Thomsonite. 

Phillipsite=(CaO,KO).Si03+Al203.Si03+5HO.  Fusi- 
bility—3,  with  slight  intumescence  5  occurs  usually  in 
twin  crystals. 
Section  2.  Giving  only  traces  or  no  water  in  a  matrass. 

Helvin=MnO,  MnS+2(MnO.BeO.FeO),  SiO3 ;  Teph- 
roite=3MnO.  SiO3.  Distinguished  from  the  other 
minerals  of  this  section  by  giving  manganese-reac- 
tions. Color  of  helvin  wax-yellow,  hardness=6 — 6.5  ; 
of  tephroite  ash-gray,  hardness=5.5 — 6. 

Hauyne  and  Lapis  Lasuli=Si03,  Al203,CaO,  KO,  S03,S, 
are  of  azure-blue  color  ;  give  sulphur-reaction,  $  107. 
Fusibility  of  the  former=4.5,  of  the  latter=3. 

Nosean  and  Skolopsite=Si03,  A1203,  CaO,  NaO,  SO3,  of 
gray  or  brownish  color;  give  sulphur-reaction,  §  107. 
Fusibility  of  nosean=4.5  ;  of  skolopsite=3  (with  in- 
tumescence like  idocrase). 

Sodalite=NaCl  +  3NaO.  Si03+  3  (A120S,  SiO3)  j  Eudi- 
alyte=Si03,  ZrO3,  CaO,  NaO,  FeO,  Cl,  give  the  chlo- 
rine-reaction, $  65.  The  former  fuses  to  a  transparent 
colorless  glass,  the  latter  to  a  grayish-green  scoria  or 
opaque  glass. 

Wollastonite=3CaO,  SiO8.    The  hydrochloric  acid  solu- 
11* 


126 


tion  gives  no,  or  only  a  very  slight,  precipitate  with 
ammonia. 

Eukolite=Si03,  NbO3,  Zr203,  CaO,  NaO.  By  boiling 
the  hydrochloric  acid  solution  with  tin,  it  assumes  a 
fine  blue  color  on  reaching  a  certain  degree  of  con- 
centration. See  also  Wohlerite. 

Nepheline=2(NaO.  KO),  Si03+2  (A1203,  SiO3)  ;  Mei- 
onite=3CaO.  Si03  +  2  (A1203?  SiO3) ;  Mellilite=2  (3 
|_CaO.  MgO.  NaO],  Si03)+(Al208.  Fe203),  SiO3.  The 
hydrochloric  acid  solution  is  precipitated  by  ammo- 
nia. Meionite  fuses  with  intumescence,  the  others 
quietly. 

Division  4.  Soluble  in  hydrochloric  acid  with  separation  of  silica,  with- 
out forming  a  perfect  jelly.     (It  is  sometimes  neces- 
sary to  treat  the  finely  pulverized  mineral  with  con- 
centrated acid.) 
Section  1.  Giving  water  in  a  matrass. 

Apophyllite=KO.  2  Si03+8  (CaO.SiO3)  +16HO  ;  Pec- 
tolite=3([NaO.  KO].Si03)+4(3CaO.  2Si03)+3HO; 
Okenite=3CaO,  4Si03+6HO.  The  silica  separates 
in  the  shape  of  gelatinous  lumps.  The  hydrochloric 
acid  solution  gives  no,  or  only  a  slight,  precipitate 
with  ammonia.  Pectolite  yields  but  little  water,  the 
others  much.  Fusibility  of  apophyllitc=1.5,  forming  a 
white  vesicular  glass  ;  of  okenite=2.5 — 3,  forming  a 
porcelain-like  mass. 

Analcime  =  3  Na0.2Si03.  +  3(A1203,2  SiO3)  +  6  HO. 
Gelatinizes  like  the  preceding;  in  the  acid  solution 
ammonia  produces  a  copious  precipitate. 

Pyrosclerite=(AW.  Cr'O3),  Si03+2(3[MgO.Fe]),Si03 
+1  i  HO  j  Chonikrite=2  A1203,  Si03+3(3[MgO.  CaO. 
FeO],  SiO3)  +6HO,  are  distinguished  from  the  other 
minerals  of  this  section  by  their  inferior  hardness= 
2.5 — 3.  The  former  gives  with  fluxes  the  reactions  of 
oxide  of  chromium,  \\  67  and  68. 


127 


Brewsterite  =  (SrO.BaO),  SiO3  +  A1203, 3Si03+ 5HO  5 
characterized  by  its  hydrochloric  acid  solution  giving 
a  precipitate  with  sulphuric  acid. 

Stilbite=CaO.Si03+Al203.3Si03+5HO ;  Chabazite= 
3(CaO.NaO),2Si03+3(Al203.  2Si03)  +  18HO  ;  Preh- 
nite=2CaO.Si03+Al203.Si03+HO.  Fuse  with  in- 
tumescence to  enamel-like  masses.  Prehnite  yields 
but  little  water,  losing  by  ignition  only  4.3  per  cent. ; 
the  others  lose  from  15  to  20  per  cent. 

Meerschaum,  see  below;      Deweylite=2MgO.Si03+3 
HO.     Distinguished  by  being  much  less  fusible  than 
the   preceding    (fusibility=5) ;    the   former   absorbs 
water  with  great  avidity,  the  latter  not. 
Section  2.  Giving  only  traces  or  no  water  in  a  matrass. 

Tachylyte=3(FeO.  CaO.  NaO),  2Si03+Al203,Si03.  Fu- 
ses readily  to  a  black  shining  glass.  Hardness=6.5  j 
color  black. 

Scapolite=3(CaO.  NaO),  Si03+3(Al203.  SiO3).  Color 
light.  Hardness=5 — 5.5.  Fuses  with  intumescence  to 
a  white,  vesicular  glass. 

Wohlerite=SiO,3  NbO3,  Zr203,  CaO,  NaO.  Fusibility= 
3,  forming  a  yellowish  enamel.  The  hydrochloric 
acid  solution  gives  the  same  reaction  as  eukolite. 

Labradorite=(CaO.  NaO),  Si03+Al203.  SiO3;  Anorth- 
ite=3CaO,  Si03+3  (A1203,  SiO3).  Fusibility=3— 4, 
without  intumescence,  forming  a  colorless  glass;  hard- 
ness of  the  former=6,  of  the  latter=6 — 7.  Cleavage 
perfect. 

Lime  Garnet  (some  varieties)  =3CaO,  Si03+Al203,  SiO3. 
Fusibility=3 ;  not  cleavable. 

Sphene,  some  varieties,  see  below.  Gives  titanium-reac- 
tions, §111. 

Division  5.  Little  affected  by  hydrochloric  acid  ;  give  with  jinxes  the 
manganese-reactions. 


128 


Carpholite=Si03,  APO3,  FeO,  MnO,  Fe203,  HO.  Oc- 
curs only  in  radiated  and  stellated  tufts.  Color  straw- 
yellow  ;  silky.  Yields  water. 

Manganese  Garnet=3MnO.  Si03+Al203.Si08.  Color 
brownish-red  5  fuses  without  intumescence  ;  not  cleav- 
able. 

Epidote      (some      varieties)  =  3CaO,  Si03+2([Al«03. 
Mn203.  Fe203],  SiO3)  Fusibility=2— 2.5,  intumesces. 
Cleavable.     Color  cherry-red  to  reddish-black. 
Rhodonite=3MnO,2  SiO3.    Fusibility=3,  without  intu- 
mescence.    Color  rose-red ;  cleavable. 
Division  6.  Not  belonging  to  eitJier  of  the  preceding  divisions. 

Scheelite=CaO,W03.  Fusibility=5.  Soluble  in  hy- 
drochloric acid,  leaving  a  residue  of  tungstic  acid, 
which  is  soluble  in  ammonia,  and  which  gives  with 
S  Ph  the  characteristic  reaction  of  tungstic  acid ;  see 
Table  II. 

Lepidolite=KO,  LiO,  F,  A1203,  SiO3;  Euphyllite=Si03, 
A1203,  CaO,  HO  ;  Margarite=SiO,3  A1203,  CaO,  HO. 
Fusibility  of  lepidolite=2 ;  gives  the  lithia-reaction, 
§  89.  Fusibility  of  euphyllite=4.5,  of  margarite=4. 
Color  of  euphyllite  white  to  colorless ;  of  margarite 
grayish,  reddish-white,  yellowish.  All  three  possess 
perfect  cleavage. 

Petalite  =  3(LiO.NaO),2Si03  +  4( Al20333Si03) ;    Spo- 

dumene=3  (LiO.NaO),  2Si03  +  4  ( Ala03,  2  SiO3),  do 

not  possess  as  perfect  a  cleavage  as  the  preceding, 

and  greater  hardness ;  hardness  of  petalite=6 — G.5, 

of  spodumene=6.5 — 7.     Both  give  the  lithia-reaction, 

§  89.     Spodumene  fuses  with  intumescence  to  a  glassy 

globule ;  petalite  fuses  to  a  white  enamel. 

Diallage=3(CaO.MgO),2Si03.     Fusibility=3.5  j    cha- 

^    racterized  by  its  pearly  metallic-lustre  ;  cleaves  easily 

in  one  direction. 


129 


Harmotome=BaO,Si03-f-Al203, 2Si03+5HO.  Distin- 
guished from  the  other  minerals  of  this  division  by 
yielding  water  in  a  matrass.  Occurs  usually  in  twin 
crystals. 

Axinite=Si03,  A1208,  CaO,  FeO,  MnO,  BO3 ;  Tourma- 
line=Si03?  A1203,  FeO,  KO,  NaO,  LiO,  BO3.  Give 
the  reaction  of  boracic  acid,  §  61.  Axinite  fuses  read- 
ily with  intumescence  to  a  dark-green  glass.  Different 
varieties  of  tourmaline  show  different  fusibility.  Hard- 
ness of  axinite=6.5 — 7,  of  tourmaline=7 — 7.5. 

Diopside  (white  augite)=3CaO,  2Si03  +  3MgO,2Si08; 
Augite=3CaO,  2Si03+3(MgO.  FeO),  2Si03.  Hard- 
ness=6 ;  diopside  fuses  to  a  whitish,  augite  to  a  black 
glass.  Color  of  augite  black  or  dark-green  ;  of  diop- 
side pale  green  or  gray,  or  colorless. 

Tremolite  =  CaO.SiO3  +  3Mg0.2Si03 ;  Hornblende  = 
CaO.Si03  +  3(MgO.FeO),  2Si03.  Hardness  =  5.5  j 
fusibility =3 — 4,  tremolite  fuses  to  a  white  or  light- 
colored  glass,  hornblende  to  a  black  or  gray  glass  ; 
the  former  is  colorless  or  white,  or  of  light  green, 
yellow,  or  gray  color ;  hornblende  is  green  or 
black. 

Sphene  =  2(CaO,  Si03)  +  CaO,  3Ti02.  Fusibility  =3. 
Hardness=5 — 5.5.  Gives  the  titanium-reaction,  $111. 
Imperfectly  soluble  in  hydrochloric  acid. 

Orthoclase  =  KO.SiO3  +  Al203,3Si03  j  Albite  =  NaO, 
Si03+Al203,  3Si03.  Hardness=6.  Fuse  without 
intumescence;  fusibility  of  orthoclase=5,  of  albite— 
4 ;  the  latter  colors  the  flame  yellow.  Not  soluble  in 
acids.  With  solution  of  cobalt  become  blue  on  the 
edges,  $  44. 

Zoisite=3CaO.Si03-f  2(A1203,  SiO3) ;  Epidote  =  CaO, 
Si03-f  2([Al203.Fe208],Si03).  Hardness=6.5.  Fu- 
sibility=3 — 3.5  ;  fuse  with  intumescence,  zoisite  to  a 


130 


white  or  yellowish  slag,  epidote  to  a  black  or  dark 
brown  slag.  Color  of  zoisite  gray,  yellowish-gray, 
grayish-white;  of  epidote  green. 

Lime  Garnet  =  3CaO,  SiO3  -f  A1203,  SiO3  ;  Idocrase= 
3CaO,  Si03+  (Fe203.  A1203),  SiO8 ;  Pyrope  =  (MgO. 
FeO.  CaO),  Si03+(Al2Q3.  Cr203),  SiO3.  Hardness= 
6.5 — 7.5.  Fusibility  of  lime  garnet  and  idocrase=3, 
of  pyrope=4.5.  Idocrase  possesses  cleavage,  the 
others  not.  Pyrope  gives  with  the  fluxes  the  chro- 
mium-reactions. 

(See  also,  emerald,  euclase,  iolite,  biotite,  and  musco- 
vite.) 

Obsidian,  Pitchstone,  Pearlstone,  and  Pumice=Si03, 
A1203,  NaO,  KO,  HO,  are  amorphous.  Fusibility 
3.5 — 4,  fuse  with  intumescence  to  porcelain-like 
masses,  or  white  vesicular  glasses.  Lustre  of  obsidian 
glassy,  of  pitchstone  greasy,  of  pearlstone  pearly; 
pumice  is  characterized  by  its  porosity. 
CLASS  III.  INFUSIBLE,  OR  FUSIBILITY  ABOVE  5. 

Division  1.  After  ignition  moistened  with  solution  of  cobalt  and  again 
ignited,  assume  a  bright-blue  color. 

With  the  hard,  anhydrous  minerals  of  this  division,  the 
color  is  best  seen  by  reducing  the  substance  to  a  fine 
powder  and  moistening  this  with  the  solution  of  cobalt. 
The  color  appears  only  after  cooling. 
Section  1.  Giving  much  water  in  a  matrass. 

Alunite=S03,  APO3,  KO,  HO  ;  Websterite=Al203,Si03 
+9HO.  Give  a  sulphur-reaction,  §  107.  Webster- 
ite  is  readily  soluble  in  hydrochloric  acid;  alunite  not 
visibly  affected. 

(See  also,  ammonia  alum,  and  potash  alum.) 

Plumbo-Resinite,  see  §176. 

Calamine,  see  $  214. 

Wavellite  =  4A1203,  3P05  +  18HO  ;  Gibbsite  =  A1203, 


131 


P05+8HO  ;  Peganite=2Al203,  P05+6HO;  Fischer- 
ite=2A!203,  P05+2HO.  Soluble  to  a  great  extent 
in  hydrate  of  potassa.  Give  the  reactions  of  phos- 
phoric acid,  $$  94  and  95.  The  former  two  occur 
usually  in  globular  concretions  of  radiated  structure, 
the  latter  two  minutely  crystalline.  Peganite  loses 
on  ignition  24  per  cent,  of  water,  wavellite  27,  fischer- 
ite  29,  gibbsite,  35. 

Diaspore  =  A1203,  HO  ;  Clintonite  =  SiO3,  A1203,  CaO, 
MgO,  HO.  Diaspore  is  but  slightly  soluble  in  hydrate 
of  potassa  ;  clintonite  insoluble ;  the  former  loses  on 
ignition  11£  per  cent  of  water,  the  latter  4£.  Hard- 
ness of  diaspore=6.5 — 7  j  of  clintonite=4 — 5. 

Allophane  =  3  A1203,  2  Si03+15  HO  ;  Halloysite  =  3 
A1203, 4Si03+12HO  ;  Ochran=Al203,  Si03  +  6HO  ; 
Collyrite=3Al203,  Si03+15HO.  Decomposed  by  hy- 
drochloric acid  with  separation  of  gelatinous  silica. 
Hardness  of  allophane=3,  of  the  others=l — 2.  Hal- 
loysite loses  on  ignition  16  per  cent  of  water,  ochran 
21,  collyrite  33£. 

Pholerite=Al203,  Si03+2HO  ;  Cimolite=Al203,  3SiOs 
+3HO;  Kaolin  =  3 Al203,4Si03  +  6HO  and  2A1203, 
3Si03+6HO,  are  all  very  soft  and  earthy,  and  but 
little  affected  by  acids;  lose  on  ignition  from  12  to  16 
per  cent,  of  water.  Nearly  related  to  these  minerals 
are  the  various  varieties  of  common  clay,  some  varie- 
ties of  lithomarge  (with  14  per  cent.  of»water),  and 
bole  with  24 — 26  per  cent,  of  water ;  the  clays  become 
plastic  with  water,  the  latter  two  not. 
Section  II.  Giving  little  or  no  water  in  a  matrass. 

Lazulite=P05,  A1203,  MgO,  FeO,  HO.  Gives  the  reac- 
tion of  phosphoric  acid,  \  74.  Heated,  loses  its  blue 
color  and  becomes  white.  Not  affected  by  acids. 

Willemite=3ZnO,  SiO3.     With  solution  of  cobalt  (§  44) 


132 


becomes  blue,  and  green  in  spots.  Gelatinizes  with 
hydrochloric  acid. 

Myelin  =  2(A1203,  SiO3)  +  HO  ;  Agalmatolite  =  SiO3, 
A1203,  KO,  HO  ;  Pyrophyllite  =  BMgO,  2 SiO3  +  9 
(A1203,  Si03)-f-9HO.  Are  very  soft,  hardness  1—2. 
Pyrophyllite  is  foliated  like  talc ;  before  the  Blp  swells 
up  and  spreads  out  into  fan-like  shapes,  increasing  to 
about  20  times  its  former  bulk.  The  others  do  not 
change  before  the  Blp.  Myelin  is  partially  decom- 
posed by  hydrochloric  acid  ;  agalmatolite  not  affected. 

Muscovite=KO,Si03+4(Al203,Si03).  Cleavage  eminent 
in  one  direction  ;  folia  elastic.  Does  not  swell  percepti- 
bly before  the  Blp,  fusible  in  very  thin  laminee.  Not 
affected  by  acids.  Hardness=2.5. 

Disterrite  (variety  of  clintonite),  cleavable  in  one  direc- 
tion. Hardness  4 — 5.  Decomposed  by  concentrated 
sulphuric  acid. 

Andalusite=4Al*Os,  3Si03;  Kyanite=3Al203,  2Si03are 
but  little  affected  by  acids.  Kyanite  occurs  generally 
in  bladed  crystallizations ;  hardness=6 — 7.  Hardness 
of  andalusite=7.5,  but  variety  chiastolite  varies  in 
hardness  from  3  to  7.5. 

Topaz=2Al2F3  +  5  ( Al203Si03) ;  Lithia  Tourmaline  = 
SiO3,  BO3,  Al203,MnO,LiO,KO.  Not  affected  by  acids. 
Not  completely  soluble  in  SPh,  the  glass  becomes 
opalescent  on  cooling.  Topaz  on  being  ignited  remains 
transparent  and  does  not  swell ;  tourmaline  becomes 
white  and  swells.  Topaz  is  cleavable  in  one  direction. 
hardness=8;  tourmaline  is  not  cleavable,hardness=6.5. 

Corundum  (sapphire)=A!203 ;  Chrysoberyl=BeO,  A1203, 
Not  affected  by  acids.  When  pulverized,  slowly  but 
completely  soluble  in  SPh ;  the  glass  does  not  opal- 
esce  on  cooling.  Hardness  of  chrysoberyl=8.5,  of 


133 


corundum=9 ;  color  of  the  former  usually  green,  ot 
the  latter  blue,  red,  yellow,  brown. 

(Some  varieties  of  Spinel  and  Leucite  assume  a  blue  color 

with  solution  of  cobalt.) 

Division  2.  Moistened  with  solution  of  cobalt  and  ignited,  assume  a 
green  color. 

It  is  sufficient  to  heat  to  redness.  The  minerals  of  this 
division  give  a  coating  of  oxide  of  zinc  on  charcoal, 
§25. 

Smithsonite,  see  §  213. 

Zinc  Bloom=(ZnO,C02-f-HO)+2(ZnO,HO).  Dissolves 
readily  in  hydrochloric  acid  with  effervescence;  the 
solution  gives  with  ammonia  a  white  precipitate,  so- 
luble in  an  excess  of  the  reagent.  Yields  water  in  a 
matrass. 

Willemite=3ZnO,  SiO8  ;  Calamine,  see  §214.  Gela- 
tinize with  hydrochloric  acid.  Calamine  yields  water, 
willemite  not.  With  solution  of  cobalt  assume  a  green 
color  only  in  spots. 

(See  also  Blende  and  Goslarite.) 

Division  3.  After  ignition  have  an  alkaline  reaction,  and  change  into 
blue  the  color  of  a  moistened  red  litmus-paper. 

Brucite=MgO,  HO  ;  Hydromagnesite=MgO,  4HO+3 
(MgO,C02).  Yield  much  water  in  a  matrass,  unlike 
the  other  minerals  of  this  division.  Brucite  dissolves 
in  hydrochloric  acid  without  effervescence,  hydromag- 
nesite  with  effervescence  ;  the  concentrated  solutions 
are  not  precipitated  by  sulphuric  acid.  Laricasterite 
is  a  mixture  of  brucite  and  hydromagnesite.  Nem- 
alite  is  a  fibrous  variety  of  brucite,  of  silky  lustre. 

Calcite=CaO.C02;    Arragonite=CaO.  CO*.     Dissolve 
readily  and  with  effervescence  in  dilute  cold  hydro- 
chloric acid;  the  concentrated  (but  not  the  dilute) 
12 


134 


solution  gives  a  precipitate  with  sulphuric  acid.     Ar- 
ragonite  falls  to  powder  before  the  Blp,  calcite  not. 
Dolomite=MgO.  C02+CaO.  CO2;  Magnesite=MgO.C02 
Do  not,  or  but  slightly,  effervesce  with  cold  dilute  hy- 
drochloric acid,  but  dissolve  readily  on  application  of 
heat.     The  concentrated  solution  of  the  former  gives 
a  precipitate  with  sulphuric  acid,  that  of  the  latter  not. 
A  similar  behavior  shows  the  Breunnerite=(MgO.  FeO. 
MnO),C02,  which  on  ignition   becomes  black   and 
slightly  magnetic ;  and  some  varieties  of  Chalybite, 
see  $  163,  and  Diallogite,  see  $  185. 
Strontianite  =  Sr  O.C  O2 ;     Barytocalcite  =  Ba  O.C  O2  + 
CaO.  CO2.     Dissolve  with  effervescence  in  dilute  hy- 
drochloric acid ;  the  solution,  even  if  largely  diluted 
with  water,  gives  a  precipitate  with  sulphuric  acid. 
Strontianite  colors  the  flame  red,  §  34  ;  barytocalcite 
yellowish-green,  $  35. 
(See  also  Yttrocerite). 

Division  4.  Completely  soluble,  or  nearly  so,  in  hydrochloric  or  nitric 
acid  without  gelatinizing  or  leaving  a  perceptible  resi- 
due of  silica. 

Chalybite,  see  $  163  ;  Breunnerite,see  preceding  division ; 
Diallogite,  see  $  185  ;  Emerald  Nickel,  see  $  195. 
Dissolve  in  heated  hydrochloric  acid  with  efferves- 
cence. 

Limonite,  see  \  155;  Golhite=Fe203,HO.  Become 
black  and  magnetic  in  reduction  flame.  Dissolve  in 
hydrochloric  acid  without  effervescence.  Gothite  oc- 
curs crystallized  and  cleaves  distinctly  in  one  direc- 
tion; loses  10  per  cent,  on  ignition;  limonite  loses 
14 \  percent. 

(See  also  Hematite  which  in  some  varieties  is  without 

metallic  lustre  ;  readily  distinguished  by  red  streak.) 

Blende,  see  \  212;    Marmatite=FeS+3ZnS ;    Green- 


135 


ockite=CdS.  Dissolve  in  hydrochloric  acid  with  evo- 
lution of  sulphuretted  hydrogen.  Give  the  sulphur- 
reaction,  $  107.  Greenockite  gives  on  charcoal  a 
coating  of  oxide  of  cadmium,  $  24,  the  others  of  oxide 
of  zinc,  $  25.  Marmatite  gives  after  calcination  with 
the  fluxes  the  reactions  of  iron. 

Wad,  see  %  184;  Zincite,  see  $  211. 

Earthy  Cobalt,  see  g  133.     Some  varieties'are  fusible. 

Pitchblende=UO,Us03;  Zippeite=U«03+xHO.  Give 
with  the  fluxes  the  reactions  of  sesquioxide  of  uranium 
{/Table  II].  Give  with  nitric  acid  a  yellow  solution  in 
which  ammonia  produces  a. sulphur-yellow  precipitate. 
Pitchblende  is  black,  zippeite  yellow. 

Chrome  Ochre=Cra03.  Gives  with  fluxes  the  reactions 
of  sesquioxide  of  chromium  [Table  II] .  Forms  with 
hydrate  of  potassa  a  green  solution. 

Turquois=PO,5  A120*,  HO,  CuO.  Color  sky-blue  and 
green.  Gives  the  copper-reaction,  §74.  Yields  much 
water  in  a  matrass. 

Apatite=3(3CaO.PO*)-fCa(Cl,F).  Gives  the  phos- 
phoric acid  reaction,  $  94.  Fusibility=5.  Soluble  in 
nitric  acid.  Gives  the  fluorine-reaction,^  76  (always?) 

Monazite=POs,  CeO,  LaO,  ThO.  Infusible.  Gives  the 
phosphoric  acid  reaction,  \  94.  Soluble  in  hydro- 
chloric acid.  Minute  tabular  crystals  of  reddish-brown 
color. 

Childrenite=PO6,Al208,FeO,  MnO,  HO,  Gives  the 
phosphoric  acid  reaction,  $  94.  With  the  flaxes  gives 
the  reaction  of  iron  and  manganese.  In  hydrochloric 
acid  soluble  with  difficulty.  Yields  much  water. 

Polycrase=Ti02,  NbO3,  Z^O8,  Fe*0s,  Ce203,  U203,  &c. 
Decrepitates,  but  infusible.  Color  black.  On  fusing 
the  pulverized  mineral  with  hydrate  of  potassa,  boil- 
ing the  fused  mass  with  hydrochloric  acid,  filtering, 


136 


and  boiling  the  filtrate  with  tin-foil,  the  liquid  assumes 
a  blue  color  on  reaching  a  certain  degree  of  concen- 
tration ;  the  color  disappears  on  addition  of  water. 

Fluocerite=CeF.     Gives  the  reactions  of  fluorine,  §75, 
and  of  sesquioxide  of  cerium,  Table  II.   Yttrocerite= 
F,  CaO,  YO,  Ce203,  behaves  similarly. 
Division  5.  With  hydrochloric  acid  form  a  jetty,  or  are  decomposed 

with  separation  of  silica  without  gelatinizing. 
Section  1.  Giving  water  in  a  matrass. 

Dioptase=3CuO,  2Si03+3HO ;  Chrysocolla,  see  g  149. 
Behave  alike  before  the  Blp  j  the  former  gelatinizes 
with  acids,  the  latter  not. 

Thorite  =  3ThO,  Si08+3HO  ;  Cerite  =  3CeO,  Si08-f 
3HO.  Gelatinize  with  hydrochloric  acid.  Color  of 
thorite  orange-yellow  or  black,  hardness=4.5 — 5  ;  of 
cerite,  brown  to  red  passing  into  gray,  hardness=5.5. 

Chloropal=Fe203,  2SiO»-f  3HO.  Color  yellowish-green, 
amorphous,  of  an  opal-like  appearance.  Becomes 
magnetic  by  ignition  j  gelatinizes.  Small  pieces  when 
thrown  into  a  concentrated  solution  of  hydrate  of 
potassa  lose  the  green  color  and  become  dark-brown. 
Hardness=2— 3. 

Hisingerite=Fea05J,  Si03+  3HO  ;  Xylotile  =  Fe203, 
3Si03+3MgO,  2Si03+5HO.  Become  magnetic  by 
ignition.  Readily  decomposed  by  hydrochloric  acid. 
Hisingerite  is  black,  imperfectly  crystallized  and  cleav- 
able  in  one  direction;  xylotile  is  light  or  dark  brown, 
of  fibrous,  woody  structure. 

Meerschaum=MgO,  Si03+2HO  Gelatinizes  with  hy- 
drochloric acid  ;  very  light ;  absorbs  water  with  great 
avidity;  gives  the  magnesia-reaction  with  solution  of 
cobalt,  \  44. 

Schiller-Spar=3([MgO.  FeO],  SiOs)  +  2(MgO,2HO) . 
Chrysotile  =  3MgO,  2Si03+MgO,3HO.  Possess  a 


137 


metallic  pearly  lustre ;  the  former  is  massive,  cleav- 
able  ;  the  latter  fibrous.  By  ignition  schiller-spar  be- 
comes brown,  chrysotile  white.  Both  are  decomposed 
by  hydrochloric  acid,  or  more  readily  by  sulphuric 
acid,  without  gelatinizing. 

Serpentine  =  2  (3MgO,  2Si03)  +  3  (MgO,  2HO).  De* 
composed  by  concentrated  hydrochloric  acid  without 
gelatinizing.  Usually  massive  and  compact ;  hard- 
ness=3 — 4;  loss  by  ignition  12 — 13  per  cent.  Of 
similar  composition,  and  showing  a  similar  behavior, 
are  the  following  minerals,  which,  however,  possess 
crystalline  structure  and  cleavage :  Picrophyll,  hard- 
ness=2.5,  loss  by  ignition  10£  per  cent. ;  Picrosmine, 
hardness=2.7,  loss  by  ignition  9  per  cent. ;  Marmo- 
lite,  hardness=2.5 — 3,  loss  by  ignition  15.7  per  cent. ; 
Kaemmererite,  hardness=1.5 — 2,  loss  by  ignition  13 
per  cent. 

(See  also  Chlorite  and  Ripidolite  which  are  with  difficulty 
decomposed  by  concentrated  hydrochloric  acid.) 

Antigorite=3  (MgO.  FeO),  2Si08+MgO,  HO  j  Monra- 
dite=4(3[MgO.FeO],2Si03)+3HO ;  Neolite=3MgO, 
2Si03-f-HO.  Decomposable  by  concentrated  hydro- 
chloric acid  without  gelatinizing.  Loss  by  ignition 
4 — 6  per  cent.  Antigorite  occurs  in  foliated  masses, 
hardness=2.5 ;  monradite,  hardness=6  5  neolite  in 
silky  fibres  or  massive,  hardness— 1. 

(See  also  some  varieties  of  Clintonite,  hardness=4 — 5.) 
Section  2.  Giving  only  traces  or  no  water  in  a  matrass. 

Gadolinite  =  SiO3,  YO,  FeO,  CeO,  Be20s  j  Gehlenite  = 
2  (3CaO,  Si03)+2  ( A120».  Fe203),  SiO3.  Gelatinize 
with  hydrochloric  acid.  Gadolinite  swells  before  the 
Blp  into  cauliflower-like  masses,  and  sometimes  exhi- 
bits a  vivid  glow  5  thin  splinters  fusible  on  the  edges  ; 
color  black  to  blackish-green;  hardness=6.5 — 7. 
12* 


138 


Gehlenite  is  also  fusible  in  very  thin  splinters ;  color 
gray  to  grayish- white  ;  hardness=5.5 — 6. 

Chrysolite=3MgO,  SiO3;  Chondrodite=2  (3MgO,  SiO8) 
-f  MgF.  Gelatinize  with  hydrochloric  acid.  Color  of 
the  former  green,  of  the  latter  mostly  white,  yellow,  or 
brown.  Chondrodite  gives  the  fluorine-reaction,  §  76. 

Boltonite  (a  variety  of  pyroxene)  =  SiO3,  MgO,  FeO, 
A1203.  Cleavage  distinct  in  one  direction.  Color 
yellow.  (See  also  Clintonite.) 

Leucite  =  3KO,2Si03+3(Al«08,2Si03).  Decomposed 
by  hydrochloric  acid,  the  silica  separating  as  a  fine 
powder  ;  some  varieties  become  blue  with  solution  of 
cobalt  ;  occurs  usually  in  trapezohedrons.  Color  gray- 
ish or  white. 
Division  6.  Not  belonging  to  either  of  the  preceding  divisions. 

The  remaining  minerals  which  cannot  be  classed  under 
any  of  the  preceding  divisions,  may  be  divided  ac- 
cording to  their  hardness  in  two  sections. 
Section  1.  Hardness  below  7. 

Biotite  (hexagonal  mica)  =  ( AP 0».  Fe2 O8),  SiO8  +  3 
(MgO.  KO),  SiO8;  Muscovite  (oblique  mica)=KO, 
Si03  +  4  (A1203,  SiO3)  j  Talc  =  6MgO,  5Si03+2HO. 
Give  little  or  no  water  in  a  matrass ;  talc  loses  at 
most  5  per  cent.  Cleavage  eminent  in  one  direction. 
Hardness  of  biotite=2.5 — 3,  of  muscovite=2 — 2.5, 
of  talc=l — 1.5.  Biotite  is  decomposed  by  concen- 
trated sulphuric  acid,  the  others  not.  The  lamina?  of 
biotite  and  muscovite  are  elastic,  of  talc  not.  Soap- 
stone  or  steatite  is  a  massive,  usually  compact  variety 
of  talc  ;  very  greasy  to  the  feel,  or  like  soap  (see  also 
Pyrophyllite). 

Chlorite  =  2(MgO,Al203)+3(2[MgO.Fe],SiOs)+6HO; 
Ripidolite  =  (MgO.  FeO),  Si03+  (A1203.  Fe203),  SiO8 
+4  (MgO,  HO).  Loses  by  ignition  12  per  cent,  of 


139 


water.  Cleavage  eminent  in  one  direction,  larainse 
not  elastic  (chlorite  often  massive  granular).  Hard- 
ness of  chlorite=2 — 2.5  ;  of  ripidolite=l — 2.  De- 
composed by  concentrated  hydrochloric  acid  with 
continued  boiling,  more  readily  by  sulphuric  acid. 
Ripidolite  fuses  with  difficulty  (=5.5)  to  a  grayish- 
yellow  enamel,  chlorite  becomes  black  and  slightly 
magnetic.  A  similar  behavior  shows  the  Chloritoid ; 
hardness— 5.5 — 6. 

Bronzite  (hypersthene)=  SMgO,  2Si08  +  3  (CaO.  FeO), 
2Si05 ;  Anthophyllite  ==  FeO,  SiO3  -f  SMgO,  2SiO*. 
Cleavage  of  bronzite  very  perfect  in  one  direction  ; 
anthophyllite  cleaves  in  two  directions.  The  former 
is  of  clove-brown  or  pinchbeck-brown  color,  with  a 
pearly-metallic  lustre ;  the  lustre  of  anthophyllite  is 
much  less  perfect.  Hardness=5 — 5.5. 

Wolframite=W08,  is  soluble  in  hydrate  of  potassa;  the 
solution  gives  with  nitric  acid  a  yellow  precipitate 
which  on  boiling  becomes  lemon-yellow.  Occurs  in 
soft,  earthy,  yellow  masses. 

Scheelite=CaO,W03.  Fusibility=5 ;  hardness=4.5— 5. 
The  pulverized  mineral,  on  being  boiled  with  nitric 
acid,  leaves  a  lemon-yellow  residue  of  tungstic  acid. 
Gives  the  reactions  of  tungstic  acid  [Table  II]. 

Cassiterite,  see  $  209. 

Anatase,  Rutile,  and  Brookite=TiO*.  Give  the  reactions 
of  titanic  acid  [Table  II].  On  fusing  the  pulverized 
minerals  with  hydrate  of  potassa,  dissolving  the  fused 
mass  in  hydrochloric  acid  and  boiling  the  solution  with 
metallic  tin,  it  assumes  a  violet  color,  which  turns  to 
red  on  addition  of  water.  Color  of  anatase,  various 
shades  of  brown  passing  into  indigo-blue ;  of  rutile 
mostly  brownish-red  or  red,  sometimes  yellowish  or 
black ;  of  brookite,  hair-brown,  yellowish  or  reddish 


140 


(variety  arkansite  is  iron-black).  Hardness  of  anatase 
=5.5 — 6 ;  of  rutile=6— 6.5  ;  of  brookite=5.5— 6. 

Aeschynite  and  Pyrochlore=Nb03,  TiO2,  Zr203,  Ce203, 
CaO,  &c.  Treated  like  the  preceding  with  potassa, 
&c.,  the  solution  on  reaching  a  certain  degree  of  con- 
centration assumes  a  fine-blue  color,  which,  on  addi- 
tion of  water,  does  not  change  to  red,  but  gradually 
disappears.  Aeschynite  swells  before  the  Blp  and 
turns  yellow ;  pyrochlore  does  not  swell  and  becomes 
grayish. 

Opal=Si03+xHO.  Before  the  Blp  yields  water  and 
becomes  opaque ;  fuses  with  carbonate  of  soda  to  a 
clear  bead,  with  effervescence.  Infusible.  Boiled  with 
hydrate  of  potassa,  it  dissolves  completely  or  to  a 
great  extent ;  the  solution  gives  a  gelatinous  precipi- 
tate with  chloride  of  ammonium.  Hardness=6 — 6.5. 

Xenotime=3YO,  PO5.  Color,  various  shades  of  brown 
or  flesh-red.  Hardness=4 — 5.  Gives  the  phosphoric 
acid  reaction,  §  94.  Infusible.  With  salt  of  phos- 
phorous dissolves  with  great  difficulty  to  a  colorless 
glass. 

[See  also  Childrenite  and  Orthoclase.] 
Section  2.  Hardness=7,  or  above. 

[See  Cassiterite,  Rutile,  and  Opal  of  the  preceding  section 
whose  hardness  sometimes  approaches  7.] 

Quartz=Si03.  The  various  varieties  of  quartz,  as  rock- 
crystal,  amethyst,  hornstone,  flint,  chalcedony,  &c., 
are  infusible  and  unalterable  before  the  Blp,  and  fuse 
with  carbonate  of  soda  to  a  transparent  bead,  with 
effervescence.  Hardness=Y. 

Iolite=2  (3  [MgO.FeO],2Si03)+5  (Al203,Si03)  j  Stau- 
rotide=2(Al203.Fe303),Si05.  Hardness=7— 7.5.  Do 
not  fuse  to  a  transparent  glass  with  carbonate  of  soda. 
Fusibility  of  iolite=5 — 5.5;  color  blue,  grayish. 


141 


Staurotide  is  infusible ;  color  brownish-red,  brown ; 
crystals  often  cruciform. 

Beryl=3BeO,  2Si08+Al203,  2Si08 ;  Euclase=2(3BeO, 
Si03)+2Al203,  SiO3;  Phenacite=3BeO,Si03;  Zircon 
=Zr703,  SiO3.  Hardness=7.5.  Beryl  and  euclase 
turn  milk-white  with  strong  heat  and  become  rounded 
on  the  edges  ;  beryl  crystallizes  in  hexagonal  prisms, 
and  possesses  pretty  distinct  basal  cleavage,  color 
usually  pale-green  or  emerald-green  ;  euclase  crystal- 
lizes in  clinorhombic  prisms  and  possesses  distinct 
cleavage  in  two  directions  at  right  angles  to  each 
other;  color  pale  mountain-green  passing  into  blue 
and  white.  Phenacite  and  zircon  do  not  change 
before  the  blowpipe,  excepting  that  zircon  becomes 
colorless  ;  color  red,  yellow,  or  colorless,  zircon  some- 
times brown  or  gray;  phenacite  is  a  little  harder 
(=8)  than  zircon. 

Ouvarovite  (lime-chrome-garnet)  =  3Ca03SiOs+  Ci^O8, 
SiO8.  Infusible.  Hardness=7.5— 8.  Gives  with  fluxes 
the  chromium  reactions  [Table  II]. 

Spinel  =  MgO,  Al'O3  j  Pleonaste  =  (MgO.FeO),Al203; 
Gahnite=(ZnO.MgO),Si03.  Hardness=7.5— 8.  Oc- 
cur almost  exclusively  in  octahedral  crystals.  Spinel 
and  pleonaste,  when  pulverized,  are  soluble  in  salt 
of  phosphorus  ;  color  of  spinel  red,  blue,  brownish ; 
of  pleonaste  black.  Gahnite  is  almost  insoluble  in 
salt  of  phosphorus  and  borax  ;  color  dark-green  or 
black.  Kreittonite  is  a  black  spinel  containing  zinc 
and  iron,  slightly  magnetic  before  ignition. 

Diamond=C.  Characterized  by  its  hardness,  which  sur- 
passes that  of  corundum. 


TABLES, 


144 


TABLE  I.— BEHAVIOR  OF  THE  ALKALINE 

BEFORE  THE 


Gn  Ch  alone,  and  in  the 
forceps. 

With  Carbonate  of  Soda 
on  Ch. 

1.  BARYTA. 
BaO. 

The  Hydrate  fuses,  boils, 
intumesces  and  is  finally 
absorbed  by  the  Ch.  The 
Carbonate  fuses  readily  to 
a  transparent  glass,  which, 
on  cooling,  becomes  enam- 
el-white. In  the  forceps  it 
colors  the  outer  flame  yel- 
lowish-green. 

Fuses  with  Sd  to  a  homo- 
geneous mass,  which  is  ab- 
sorbed by  the  Ch. 

2.  STRONTIA. 
SrO. 

The  Hydrate  behaves  like 
hydrate  of  Baryta.  The 
Carbonate  fuses  only  at  the 
edges,  and  swells  out  in 
arborescent  ramifications 
which  emit  a  brilliant  light, 
and,  when  heated  with  the 
KF1,  impart  to  it  a  reddish 
tinge  ;  shows  after  cooling 
alkaline  reaction.  In  the 
forceps,  colors  the  outer 
flame  purple. 

Caustic  Strontia  is  inso- 
luble. The  Carbonate, 
mixed  with  its  own  volume 
of  Sd,  fuses  into  a  limpid 
glass,  which  becomes  en- 
amel white  on  cooling.  At 
a  greater  heat  the  mass 
enters  into  ebullition,  and 
caustic  Strontia  is  formed, 
which  is  absorbed  by  the 
Ch. 

3.  LIME. 
CaO. 

Caustic  Lime  suffers  no 
alteration.  The  Carbonate 
loses  carbonic  acid,  be- 
comes whiter  and  more  lu- 
minous, and  shows  after 
cooling  alkaline  reaction. 
In  the  forceps  it  colors  the 
outer  flame  pale-red. 

Insoluble.  The  Sd  pas- 
ses into  the  Ch,  and  leaves 
the  Lime  unaltered  on  its 
surface. 

4.  MAGNESIA. 
MgO. 

Undergoes  no  alterations. 
The  Carbonate  becomes 
caustic  and  luminous. 

It  behaves  like  Lime. 

5.  ALUMINA. 
A12Q3. 

Not  changed. 

Forms  an  infusible  com- 
pound, with  slight  intu- 
mescence. The  excess  of 
Sd  is  absorbed  by  the  Ch. 

145 

EARTHS  AND  THE  EARTHS  PROPER 
BLOWPIPE. 


With  Ex  on  Platinum  Wire. 


With  SPh  on  Platinum  Wire. 


The  Carbonate  dissolves  with  ef- 
fervescence to  a  limpid  glass  which, 
•when  in  a  certain  state  of  saturation, 
may  be  made  opaque  by  flaming ; 
when  still  moresaturateditbecom.es 
opaque  on  cooling,  even  without 
flaming. 


As  with  Borax. 


Presents  the  same  phenomena  as 
Baryta. 


Presents  the  same  phenomena 
Baryta. 


Readily  dissolved  to  a  limpid 
glass,  which  becomes  opaque  by 
flaming.  The  Carbonate  dissolves 
with  effervescence.  On  a  large  ad- 
dition of  Lime  the  glass  crystallizes 
on  cooling,  but  does  not  become 
enamel-white. 


Soluble  in  large  quantities  to  a 
limpid  glass  which,  when  sufficient 
Lime  is  present,  becomes  opaque  by 
flaming.  When  saturated,  the  glass 
becomes  enamel-white  on  cooling. 


It  behaves  like  Lime,  but  does  not 
crystallize  so  well. 


Readily  soluble  to  a  limpid  glass, 
which  becomes  opaque  by  flaming. 
When  saturated,  it  becomes  on  cool- 
ing enamel-white. 


Dissolves  slowly  to  a  limpid  glass, 
which  remains  so  on  cooling,  and 
which  cannot  be  made  cloudy  by 
flaming.  A  large  quantity  of  Alum- 
ina makes  the  glass  cloudy ;  on  cool- 
ing, it  then  assumes  a  crystalline 
surface. 


Soluble  to  a  limpid  glass,  which 
remains  clear  under  all  circumstan- 
ces. If  too  much  Alumina  is  ad- 
ded, the  undissolved  portion  be- 
comes translucent. 


13 


146 


TABLE  I.— CON- 


On  Ch  alone,  and  in  the 
forceps. 

With  Carbonate  of  Soda 
on  Ch. 

6.    GLUCINA. 
BeO. 

Not  changed. 

Insoluble. 

7.    YTTRIA. 
YO. 

Not  changed. 

Insoluble. 

8.    ZlRCONIA. 
Zr2  O3. 

Infusible,  but  emitting  a 
very  glaring  light. 

Insoluble. 

14V 


TINUED. 


With  Ex  on  Platinum    Wire. 

With  SPk  on  Platinum  Wire. 

Soluble  in  large  quantities  to  a 
limpid  glass,  which  becomes  opaque 
by  naming.  When  Glucina  is  pre- 
sent in  excess,  it  becomes  enamel- 
white  on  cooling. 

As  with  Borax. 

Like  Glucina. 

Like  Glucina. 

Like  Glucina. 

Dissolves  more  slowly 
borax. 

than  with 

148 


TABLE  II.— BEHAVIOR  OF  THE  METAL- 


Metallic    Oxides    in 
Alphabetical   Order. 

On  Charcoal  alone. 

With  Carbonate  of  Soda. 

1.  ANTIMONOUS. 
ACID. 

SbO3. 

OF1:     It  is  displaced 
•without  change,  and  de- 
posited    upon     another 
part  of  the  Ch. 
RF1  :  It  is  reduced  and 
volatilized.     A  Ct  of  an- 
timonous    acid   is   depo- 
sited  on    th  Ch,   and   a 
greenish-blue   color    im- 
parted to  the  flame. 

On  Ch  very  readily  re- 
duced in  OF1  and  RF1. 
The  metal  fumes  and 
coats  the  Ch  with  anti- 
monous  acid. 

2.  ARSENOUS 
ACID. 
AsO3. 

Volatile  below  red  heat. 

On  Ch  reduced,  with 
emission  of  arsenical 
fumes,  which  are  charac- 
terized by  a  strong  garlic 
odor. 

3.  TEROXIDE  OF 
BISMUTH. 
BiO3. 

OF1  :  On  platinum  foil 
it  fuses  readily  to  a  dark- 
brown    mass,   which    on 
cooling  becomes  pale  yel- 
low. 
On  Ch  in  OF1  and  KF1 
reduced  to  metallic  bis- 
muth, which,  with  long 
blowing,  vaporizes,  coat- 
ing the  Ch  with  yellow 
oxide.      The    Ct,    when 
touched  with   the    RF1, 
disappears  without  color- 
ing the  flame. 

Easily  reduced  to  me- 
tallic bismuth. 

4.  OXIDE  or  CAD- 
MIUM. 
CdO. 

OF1  :  On  platinum  foil 
unchanged. 
RF1  :  On  Ch  it  disap- 
pears in  a  short  time  and 
deposits  all  over  the  Ch 
a  dark-yellow  or  reddish- 
brown  powder  ;  the  color 
can  only  be  clearly  dis- 
cerned after  cooling. 

OF1:  Insoluble. 
RF1:    On    Ch    readily 
reduced  ;    the  metal  va- 
porizes  and    deposits   a 
dark  yellow  or  reddish- 
brown  Ct  on  the  Ch. 

149 


LIO  OXIDES  BEFORE  THE  BLOWPIPE. 


With  Bx  on  Platinum  Wire. 


With  SPh  on  Platinum  Wire. 


OF1 :  Dissolves  in  large  quanti- 
ties to  a  limpid  glass,  which,  while 
hot,  appears  yellowish,  but  after 
cooling  colorless. 

RF1 :  The  glass,  when  treated 
only  for  a  short  time  in  the  OF1, 
becomes  on  Ch  grayish  and  cloudy 
from  particles  of  reduced  antimony. 
With  tin  it  becomes  gray  or  black. 


OH :  Dissolves  with  effervescence 
to  a  limpid  glass,  which  while  hot 
is  slightly  yellowish. 

RF1:  On  Ch  the  saturated  bead 
becomes  at  first  cloudy,  but  after- 
wards clear  again,  owing  to  the  vo- 
latilization of  the  reduced  antimony. 
Treated  with  tin,  the  glass  becomes 
after  cooling  gray,  even  if  but  very 
little  antimonous  acid  is  present. 
With  strong  blowing  it  becomes  clear 
again. 


0 


OF1:  A  small  quantity  is  easily 
dissolved  to  a  clear  yellow  glass 
which,  on  cooling,  becomes  color- 
less. On  a  large  addition  of  oxide 
the  glass,  while  hot,  is  yellowish- 
red,  becomes  yellow  on  cooling,  and 
when  cold  is  opalescent. 

RF1:  On  Ch  the  glass  becomes 
at  first  gray  and  cloudy,  the  oxide 
is  reduced  to  metal  with  efferves- 
cence, and  the  bead  becomes  clear 
again.  An  addition  of  tin  acceler- 
ates the  process. 


OF1 :  Readily  dissolved  to  a  lim- 
pid yellow  glass  which,  on  cooling, 
becomes  colorless.  When  a  greater 
quantity  of  oxide  is  present,  the 
glass  may  be  made  enamel-white  by 
flaming,  and  on  a  still  larger  addi- 
tion it  becomes  by  itself  enamel- 
white  on  cooling. 

RF1 :  On  Ch,  particularly  when 
tin  is  added,  the  glass  remains  col- 
orless and  limpid  while  hot,  but  be- 
comes,  on  cooling,  dark-gray  and 
opaque. 


OF1:  Soluble  in  large  quantity  to 
a  limpid  yellowish  glass,  becoming 
almost  colorless  on  cooling.  When 
highly  saturated  it  may  be  made 
enamel-white  by  flaming,  and  when 
still  more  oxide  is  present  it  be- 
comes by  itself  enamel-white  on 
cooling. 

RF1 :  Placed  on  Ch  it  enters  into 
ebullition ;  the  oxide  is  reduced ; 
the  reduced  metal  vaporizes  imme- 
diately and  deposits  a  dark  yellow  Ct. 


OF1:  Soluble  in  large  quantity 
to  a  limpid  glass  which,  while  hot, 
is  yellowish,  but  colorless  when 
cold;  when  saturated  it  becomes 
enamel-white  on  cooling. 

RF1  -.  On  Ch  the  oxide  becomes 
slowly  and  imperfectly  reduced. — 
The  reduced  metal  deposits  a  very 
feeble  Ct  of  dark-yellow  color.  The 
color  is  only  clearly  seen  when  the 
mass  is  cold.  An  addition  of  tin 
facilitates  the  reduction. 


13* 


150 


TABLE  II.— CON- 


Metallic    Oxides    in 
Alphabetical   Order. 

On  Charcoal  alone. 

With    Carbonate  of  Soda. 

Insoluble.    The  Sd  pas- 

5. SESQUIOXIDE 
OF  CERIUM. 

np2f)3 

Not  changed. 

ses  into  the  Ch  :  the  ses- 
quioxide   is    reduced   to 
protoxide  which  remains 

V'vJ    \J   • 

on  the  Ch  as  a  light-gray 

powder. 

OF1  :  On  platinum  wire 

soluble  to  a  dark  yellow- 

ish-brown glass,  which  on 

cooling  becomes  opaque 

6.  SESQUIOXIDE 

and  yellow. 

OF  CHROMIUM. 

Not  changed. 

RF1:  The  glass  becomes 

Cr*O3 

opaque    and    green     on 

\jL    \J   • 

cooling.    On  Ch  it  cannot 

be  reduced  to  metal;  the 

Sd  passes  into  the  Ch,  and 

the  oxide  remains  behind 

as  a  green  powder. 

7.  OXIDE  OF  CO- 

OF1 :  Not  changed. 
RF1:  It  is  reduced  to 
metal,  but  does  not  fuse  : 

OF1.  On  platinum  wire 
a  very  small  quantity  is 
dissolved  to  a  transparent 
mass  of  a  pale  reddish 

BALT. 

the  mass  is  attracted  by 

color,   which  on   cooling 

CoO. 

the  magnet,  and  assumes 

becomes  gray. 

metallic   lustre   by  fric- 

RF1:   On   Ch  reduced 

tion. 

to  a  gray  magnetic  pow- 

der. 

OF1  :  Fuses  to  a  black 

OF1  :  On  platinum  wire 

globule,  which  becomes 

soluble  to  a  limpid  glass 

reduced  when  it  is  in  con- 

of green  color  ;  on  cool- 

8. OXIDE  OF  COP- 

tact with  the  Ch. 
RF1  :  Reduced  to  met- 

ing it   becomes    opaque 
and  white. 

PER. 
p  n 

al  at  a  temperature  below 

RF1  :  On  Ch  easily  re- 

\j\Ji\}. 

the  melting  point  of  cop- 

duced  to    metal,   which, 

per.  When  the  heat  is  in- 

when the  temperature  is 

creased  a  globule  of  me- 

sufficiently high,  fuses  to 

tallic  copper  is  obtained. 

one  or  more  globules. 

151 


TINUED. 


With  Bx  on  Platinum  Wire. 


With  SPh  on  Platinum  Wire. 


OF1 :  Soluble  to  a  limpid  glass  of 
dark-yellow  or  red  color,  which 
changes  on  cooling  to  yellow.  When 
highly  saturated  with  oxide  the  glass 
becomes  on  cooling  enamel-white. 

RF1 :  The  yellow  glass  becomes 
colorless.  A  highly  saturated  bead 
becomes  on  cooling  enamel-white 
and  crystalline. 


OF1 :  As  with  Bx,  but  on  cooling 
colorless. 

RF1 :  Perfectly  colorless,  hot  and 
cold.  Becomes  never  opaque  on 
cooling,  however  large  the  amount 
of  oxide. 


OF1:  Dissolves  but  slowly,  but 
colors  intensively.  If  little  of  the 
oxide  is  present,  the  glass,while  hot, 
is  yellow,  when  cold  yellowish- 
green  ;  with  more  oxide  it  is  dark- 
red,  while  hot,  becomes  yellow  on 
cooling,  and  when  perfectly  cold 
has  a  fine  yellowish-green  color. 

RF1 :  The  glass  is  green,  hot  and 
cold.  The  intensity  of  the  color 
depends  on  the  amount  of  oxide 
present.  Tin  causes  no  change. 


OF1:  Soluble  to  a  limpid  glass 
which,  while  hot,  appears  reddish; 
when  cold  it  has  a  fine  greeu  color. 

RF1 :  As  in  OF1. 


OF1 :  Colors  very  intensively. — 
The  glass  appears  pure  smalt-blue, 
hot  and  cold.  An  excess  of  oxide 
imparts  to  the  bead  a  deep  bluish- 
black  color. 

RF1 :  As  in  OF1. 


OF1:  As  with  Bx,  but  for  the 
same  quantity  of  oxide  the  color  is 
not  quite  so  deep. 

RF1  -.  As  in  OF1. 


OF1:  A  small  addition  of  oxide 
makes  the  glass  appear  green  while 
hot,  but  blue  when  cold.  A  large 
quantity  imparts  to  it  a  very  deep 
green  color,  while  hot,  becoming 
greenish-blue  when  cold. 

BF1 :  A  glass  containing  a  certain 
quantity  of  oxide  becomes  colorless, 
but  on  cooling  becomes  opaque  and 
red  (suboxide).  On  Ch  the  copper 
may  be  precipitated  in  the  metallic 
state,  the  bead  becoming  in  conse- 
quence colorless.  A  glass  contain- 
ing protoxide,  when  treated  on  Ch 
with  tin,  becomes  on  cooling  brown- 
ish red  and  opaque. 


OF1:  As  with  Bx,  but  for  the 
same  amount  of  oxide  the  coloration 
is  not  so  deep. 

RF1 :  A  glass  containing  a  large 
quantity  of  oxide  becomes  dark 
green,  which  in  the  moment  of 
refrigeration  changes  suddenly  to 
brownish-red  and  opaque.  A  glass 
containing  but  little  oxide,  when 
treated  on  Ch  with  tin,  appears 
colorless  while  hot,  but  becomes 
brownish-red  and  opaque  on  cool- 
ing. 


152 


TABLE  II.— CON- 


Metallic  Oxides  in 
Alphabetical    Order. 


On  Charcoal  alone. 


With  Carbonate  of  Soda, 


9. 


TEROXIDE 
GOLD. 
AuO3. 


OF 


"When  heated  to  ignition 
it  becomes  reduced  to 
metal  in  OF1  and  RF1. 
The  metal  fuses  easily  to 
a  globule.  . 


Does  not  dissolve  in  the 
Sd,  but  is  easily  reduced, 
in  both  flames.  The  met- 
al fuses  readily  to  a  glob- 
ule. The  Sd  passes  into 
the  Ch. 


10.  SESQUIOXIDE 
OF  IRON. 
Fe203. 


OF1:  Not  changed. 
RF1 :    Becomes    black 
and  magnetic. 


OF1:  Insoluble. 

RF1:  On  Ch  it  is  re- 
duced ;  the  mass,  when 
placed  in  a  mortar,  pul- 
verized, and  repeatedly 
washed  with  water  to 
remove  the  adherent  Ch 
particles,  yields  a  gray 
metallic  powder  which 
is  attracted  by  the  mag- 
net. 


11. 


BlNOXIDE  OP 

IRIDIUM. 
IrO2 


At  a  red-heat  becomes 
reduced  ;  the  reduced 
metal  is  infusible. 


OF1 :  Does  not  dissolve 
in  the  Sd,  but  becomes 
reduced ;  the  metal  can- 
not be  fused  to  a  globule. 

RF1  -.  As  in  OF1. 


Minium,  when  heated 
on  platinum  foil,  black- 
ens ;  on  increasing  the 
temperature  it  changes 
into  yellow  oxide,  which 
finally  fuses  to  a  yellow 


12. 


OXIDE  OF 
LEAD. 
PbO. 


On  Ch  in  OF1  and  RF1 
almost  instantaneously 
reduced  to  metal  which, 
with  continued  blowing, 
vaporizes,  and  covers  the 
Ch  with  yellow  oxide, 
surrounded  by  a  faint 
white  ring  of  carbonate. 
The  Ct,  when  touched 
with  the  RF1  disappears, 
imparting  to  the  flame 
an  azure-blue  tinge. 


OF1 :  On  platinum  wire 
readily  dissolved  to  a 
limpid  glass  which,  on 
cooling,  becomes  yellow- 
ish and  opaque. 

RF1:  On  Ch  reduced 
to  metal  which,  with 
continued  blowing,  cov- 
ers the  Ch  with  oxide. 


153 


TINUED. 


With  Bx  on  Platinum  Wire. 


With  SPh  on  Platinum  Wire. 


As  with  Carbonate  of  Soda. 


As  with  Carbonate  of  Soda. 


OF1 :  A  small  amount  of  oxide 
causes  the  glass  to  look  yellow  while 
hot,  colorless  when  cold.  When 
more  of  the  oxide  is  present  the 
glass,  while  hot,  appears  red,  and 
yellow  when  cold.  A  still  larger 
quantity  makes  the  glass  dark-red 
while  hot,  and  dark-yellow  when 
cold. 

RF1:  The  glass  becomes  bottle- 
green.  Treated  on  Ch  with  tin  it 
becomes,  at  first,  bottle-green,  but 
afterwards  pure  vitriol-green. 


OF1 :  When  at  a  certain  point  of 
saturation  the  glass,  while  hot,  ap- 
pears yellowish-red,  and  becomes 
on  cooling  at  first  yellow,  then 
greenish  and,  finally,  colorless.  On 
a  very  large  addition  of  oxide  it 
appears,  while  hot,  deep-red,  be- 
coming, on  cooling,  brownish-red, 
then  of  a  dirty-green  color,  and 
finally  brownish-red. 

RF1 :  A  glass  containing  but  lit- 
tle of  the  oxide  suffers  no  visible 
change.  When  more  of  the  oxide 
is  present  it  is  red  while  hot,  and, 
on  cooling,  becomes  at  first  yellow, 
then  greenish,  and  finally  reddish. 
Treated  with  tin  on  Ch  the  glass, 
on  cooling,  becomes  at  first  green, 
and  finally  colorless. 


As  with  Carbonate  of  Soda. 


As  with  Carbonate  of  Soda. 


OF1:  Easily  soluble  to  a  limpid 
yellow  glass  which,  on  cooling,  be- 
comes colorless.  If  much  oxide  is 
present  it  may  be  made  cloudy  by 
naming.  A  still  larger  addition  of 
oxide  causes  the  bead  to  become 
enamel-yellow  on  cooling. 

RF1:  The  glass  diffuses  itself 
over  the  Ch  and  becomes  cloudy. 
With  continued  blowing  the  oxide 
is  reduced  to  metal,  with  effer- 
vescence, and  the  glass  becomes 
clear  again. 


OF1:  As  with  Bx.  But  to  ob- 
tain a  glass  which  appears  yellow 
while  hot,  a  large  addition  of  the 
oxide  is  required. 

RF1 :  On  Ch  the  glass  becomes 
grayish  and  cloudy.  This  pheno- 
menon is  better  observed  when  tin 
is  added ;  but  the  glass  can  never 
be  made  quite  opaque.  If  much  of 
the  oxide  is  present  the  Cli  becomes 
coated. 


154 


TABLE  II.— CON- 


Metallic  Oxides  in 
Alphabetical  Order. 

On  Charcoal  alone. 

With  Carbonate  of  Soda. 

OF1  :  On  platinum  wire 

or  foil  a  very  small  quan- 

OF1: Insoluble.  When 

tity  dissolves  to  a  trans- 

the temperature  is  suffi- 

parent     green      mass, 

13.  SESQUIOXIDE 
OF  MANGANESE. 

ciently    high,    both    the 
sesquioxide  and  the  per- 
oxide are  converted  into 

which,    on   cooling,  be- 
comes opaque  and  blu- 
ish-green. 

Mn203. 

a  reddish-brown  powder 

RF1  :  On  Ch  it  cannot 

(MnO-fMn203). 

be  reduced  to  metal  ;  the 

RF1  :  The  same  effect. 

Sd  passes  into   the   Ch 

and  leaves  the  protoxide 

behind. 

Heated  in  a  matrass  to 

14.  PROTOXIDE 
OF  MERCURY. 

Instantly  reduced  and 
volatilized. 

redness,    it   is  reduced 
and  vaporized.     The  va- 
pors   condense    in    the 

HgO. 

neck  of  the  matrass  and 

form  a  metallic  coating. 

OF1:    Fuses,  becomes 

brown,    vaporizes,    and 
deposits  on  the  Ch  a  yel- 

OF1 :  On  platinum  wire 
dissolves  with   efferves- 

15. MOLYBDIC 

low  Ct,  which  nearest  to 
the  assay  is  crystalline. 
On   cooling  the   Ct  be- 
comes   white,    and    the 

cence  to  a  limpid  glass 
which,    on  cooling,  be- 
comes milk-white. 
RF1  :  Fuses  with  effer- 

ACID. 

crystals  colorless. 

vescence.       The    fused 

MoO. 

RF1:  The  greater  part 

mass  is  absorbed  by  the 

of  the  assay  is  absorbed 

Ch,  and  part  of  the  acid 

by  the  Ch,  and  may  be 

is     reduced     to     metal 

reduced  to  metal   at  a 

which  may  be  obtained 

sufficiently  high  temper- 
ature; the  metal  is  in  the 

as  a  steel-gray  powder. 

shape  of  a  gray  powder. 

OF1  :  Not  changed. 

RF1:  On  Ch  reduced  to 

OF1:  Insoluble. 

16.    OXTDE  OF 

NICKEL. 

metal  ;  the  spongy  mass 
cannot    be    fused   to    a 
globule,     but     assumes 

RF1:    Easily  reduced 
to  metal,  in  the  shape 
of  bright,  white  scales, 

NiO. 

metallic   lustre  by  fric- 

which are  attracted  by 

tion  :  it  is  attracted  by 

the  magnet. 

the  magnet. 

155 


TINUED. 


With  Bx  on  Platinum  Wire. 


With  SPh  on  Platinum  Wire. 


OF1:  Colors  very  intensively. — 
The  glass,  while  hot,  is  violet,  on 
cooling  it  assumes  a  reddish  tinge. 
When  much  manganese  is  added, 
the  glass  becomes  quite  black  and 
opaque  ;  but  the  color  can  be  seen 
when  the  glass,  while  soft,  is  flat- 
tened with  the  forceps. 

RF1 :  The  glass  becomes  colorless. 
If  the  color  was  very  dark,  the 
phenomenon  is  best  observed  on  Ch 
with  addition  of  tin. 


OF1 :  A  considerable  addition  of 
manganese  must  be  made  to  produce 
a  colored  glass ;  it  then  appears, 
while  hot,  brownish-violet,  and 
reddish-violet  when  cold,  but  never 
opaque.  If  the  glass  contains  so 
small  a  quantity  of  manganese  that 
it  appears  colorless,  an  addition  of 
nitre  will  produce  the  characteristic 
coloration. 

RF1 :  Becomes  very  soon  color- 
less. 


OF1:  Dissolved  in  large  quantities 
to  a  limpid  glass  which,  while  hot, 
appears  yellow,  but  colorlesss  on 
cooling.  A  very  large  amount  of 
acid  causes  the  glass  to  appear  dark 
yellow,  while  hot,  and  opaline  when 
cold. 

RF1:  A  highly  saturated  bead 
becomes  brown,  and  opaque  when 
still  more  acid  is  present. 


OF1:  Easily  soluble  to  a  limpid 
glass;  if  but  little  of  the  acid  is 
present  it  is  yellowish-green  while 
hot,  but  when  cold  almost  colorless. 
On  Ch  the  glass  becomes  very  dark, 
and  on  cooling  assumes  a  beautiful 
green  color. 

RF1 :  The  glass  assumes  a  very 
dark,  dirty-green  color  which,  on 
cooling,  becomes  beautiful  bright- 
green.  The  same  on  Ch ;  tin  deepens 
the  color  a  little. 


OF1 :  A  small  quantity  colors  the 
bead  violet,  while  hot;  when  cold 
pale  reddish-brown.  More  oxide 
makes  the  coloration  deeper. 

RF1 :  The  glass  becomes  gray  and 
cloudy,  or  even  opaque.  With  con- 
tinued blowing  the  minute  particles 
of  reduced  metal  collect  together 
and  the  glass  becomes  colorless. 
This  takes  more  readily  place  on 
Ch,  especially  when  tin  is  added. 
The  nickel  then  unites  with  the  tin 
to  a  globule. 


OF1:  Soluble  to  a  reddish  glass 
which,  on  cooling,  becomes  yellow. 
A  larger  addition  causes  the  glass 
to  appear  brownish-red  while  hot, 
and  reddish-yellow  when  cold. 

RF1  :  On  platinum  wire  not 
changed.  On  Ch  with  tin  it  becomes, 
at  first,  gray  and  opaque ;  with 
continued  blowing  the  nickel  be- 
comes reduced,  and  the  glass  clear 
again  and  colorless. 


156 


TABLE  II.— CON- 


Metallic  Oxides  in 
Alphabetical  Order. 

On  Charcoal  alone. 

With  Carbonate  of  Soda. 

17.  BINOXIDE  OP 
OSMIUM. 
OsO2. 

OF1:    Converted   into 
osmic  acid  which,  with- 
out depositing  a  Ct,  vol- 
atilizes with  its  peculiar 
pungent  odor. 
RF1:  Easily  reduced  to 
a   dark-brown    and    in- 
fusible metallic  powder. 

Easily  reduced  to  an 
infusible  metallic  pow- 
der. 

18.  PROTOXIDE 
or  PALLADIUM. 
PdO. 

Reduced  at  a  red-heat  ; 
but  the  metallic  particles 
are  infusible. 

Insoluble.  The  Sd  pas- 
ses into  the  Ch,  and 
leaves  the  Palladium  be- 
hind. 

19.  BINOXIDE  or 
PLATINUM. 
PtO2. 

Like  Palladium. 

Like  Palladium. 

\ 

20.  PROTOXIDE 
OF  SILVER. 
AgO. 

Easily  reduced  to  me- 
tallic silver,  which  unites 
to  one  or  more  globules. 

Instantly  reduced.  The 
Sd  passes  into  the  Ch, 
and  the  metal  unites  to 
one  or  more  globules. 

21.  TELLUROUS 
ACID. 
TeO2. 

OF1:  Fuses,  and  is  re- 
duced with  effervescence. 
The  reduced  metal  be- 
comes  instantly   vapor- 
ized and  covers  the  Ch 
with  tellurous  acid  ;   the 
Ct  usually  has  a  red  or 
dark-yellow  edge. 
RF1:   As  in  OF1;  the 
outer  flame  appears  of  a 
bluish-green  color. 

Soluble,  on  platinum- 
wire,   to    a   limpid   and 
colorless  glass,  which,  on 
cooling,  becomes  white. 
On   Ch   reduced    and 
volatilized,  depositing  a 
Ct  of  tellurous  acid. 

22.  BINOXIDE  OF 
TIN. 
SnO2. 

OF1  :    The    protoxide 
burns,  like  tinder,  to  bin- 
oxide.    The  binoxide  be- 
comes very  luminous  and 
appears,  while  hot,  yel- 
lowish, but  assumes,  on 
cooling,     a    dirty-white 
color. 
RF1  :  With  a  powerful 
and  continued  flame  it 
may  be  reduced  to  metal. 

OF1:  On  platinum  wire 
it  forms  with  Sd,   with 
effervescence,  an  infusi- 
ble compound. 
RF1:  On   Ch  reduced 
to  metallic  tin. 

157 


TINUED. 


With  Bx  on  Platinum  Wire. 


With  SPh  on  Platinum  Wire. 


0 


0 


OF1  and  RF1 :  Reduced,  but  not 
dissolved ;  the  metallic  particles 
cannot  be  fused  to  a  globule. 


As  with  Bx. 


Like  Palladium. 


Like  Palladium. 


OF1:  In  part  dissolved,  and  in 
part  reduced.  On  cooling,  the  glass 
becomes  opalescent  or  milk-white, 
according  to  the  amount  of  oxide 
present. 

RF1 :  The  glass  at  first  becomes 
gray,  but  afterwards  limpid  and 
colorless. 


OF1:  Imparts  to  the  bead  a 
yellowish  color.  When  much  of  the 
oxide  is  present  the  glass,  when 
cold,  is  opalescent,  and  appears 
yellowish  at  daylight,  reddish  at 
candle-light. 

RF1 :  As  with  Bx. 


OF1 :  Soluble  to  a  limpid  and 
colorless  glass  which,  on  Ch,  be- 
comes gray  from  reduced  metal. 

RF1 :  On  Ch  becomes  at  first  gray, 
afterwards  colorless.  The  Ch  be- 
comes coated  with  tellurous  acid. 


As  with  Borax. 


OF1 :  A  very  small  quantity  dis- 
solves slowly  to  a  limpid  and  color- 
less glass,  which  remains  so  on 
cooling. 

RF1 :  From  a  highly  saturated 
glass  a  part  of  the  oxide  may  be 
reduced  on  Ch. 


OF1 :  As  with  Borax. 
RF1 :  The  glass,  containing  oxide, 
suffers  no  change. 


14 


158 


TABLE  II.— CON- 


Metallic  Oxides  in  Al- 
phabetical Order. 

On   Charcoal  alone. 

With  Carbonate  of  Soda. 

OF1:  On  Chit  dissolves, 

OF1:     Assumes,      on 

with     effervescence,    to 

23.  TITANIC 
ACID. 

heating,  a  yellow  color, 
and  becomes  white  again 
on  cooling.  Suffers  no 

a     dark-yellow      glass, 
which,  on  cooling,  crys- 
tallizes.    When  cold   it 

TiO2. 

other  change. 

is  grayish-white. 

RF1  :  As  in  OF1. 

KF1:  As  inOFl;  can- 

not be  reduced  to  metal. 

OF1  :  On  platinum  wire 
it  dissolves   to  a  limpid 

and   deep-yellow  glass, 

24.  TUNGSTIC 

A^ID. 
WO3. 

OF1  :  Not  changed  ;  at 
a  very  high  temperature 
converted  into  oxide. 
RF1:  Blackens,  being 
converted     into    oxide, 
but  does  not  fuse. 

which,    on    cooling,  be- 
comes   crystalline     and 
opaque,  and  of  white  or 
yellowish  color. 
RF1  :  With  very  little 
Sdon  Ch  it  is  reduced  to 
metal  ;  with  more  Sd  it 

forms  ayellow  compound 

of  metallic  lustre,  which 

passes  into  the  Ch. 

OF1:  Insoluble.    With 

OF1  :     Infusible  ;    but 

a  certain  amount  of  Sd 

25.    SESQUIOXIDE 
or  URANIUM. 
U203. 

assumes  a  dirty  yellow- 
ish-green color. 
RF1  :  Blackens,  owing 
to  the  formation  of  prot- 

the  mass  becomes   yel- 
lowish-brown, and  with 
more  passes  into  the  Ch. 
KF1  :  As  in  OF1  ;    no 

oxide. 

reduction  to  metal  takes 

place. 

Fusible.     Where  it  is 

26.  YANADIC 
ACID. 
VO3. 

in  contact  with  the  Ch  it 
becomes  reduced  and 
passes  into  the  Ch.  The 
rest  assumes  the  lustre 

Unites    to    a    fusible 
mass  which  is  absorbed 
by  the  Ch. 

and  color  of  graphite. 

159 


TINUED. 


With 

Bx 

on 

Platinum 

Wire. 

With 

SPh 

on 

Platinum 

Wire. 

OF1:  Easily  soluble  to  a  limpid 
glass  which,  -when  containing  a 
large  quantity,  appears  yellow 
while  hot,  but  becomes  colorless  on 
cooling.  When  containing  a  very 
large  quantity  it  is  enamel-white 
when  cold. 

RF1:  When  containing  but  little 
titanic  acid  the  glass  becomes  yel- 
low ;  when  more,  dark-yellow  to 
brown.  A  saturated  glass  becomes 
enamel-blue  by  flaming. 


OF1 .  Easily  dissolved  to  a  limpid 
glass  which,  when  containing  a  large 
quantity,  appears  yellow  while  hot, 
but  becomes  colorless  on  cooling. 

RF1 :  Appears  yellow  while  hot, 
but,  on  cooling,  reddens  and  finally 
assumes  a  violet  color.  If  iron  is 
present  the  glass,  on  cooling,  be- 
comes brownish-red ;  with  tin  on 
Ch  the  glass  becomes  violet,  unless 
j  the  amount  of  iron  be  very  consid- 
erable. 


OF1 :  Like  titanic  acid. 

OF1:  A  glass,  containing  but 
little  tungstic  acid,  is  not  changed. 
When  more,  it  becomes  yellow  and, 
on  cooling,  yellowish-brown.  On 
Ch  the  same  reaction  is  produced 
with  a  less  saturated  bead.  Tin 
deepens  the  colors. 


OF1 :  Easily  dissolved  to  a  limpid 
and  colorless  bead,  which  when 
highly  saturated,  appears  yellow 
while  hot. 

RF1 :  With  little  blowing  the  glass 
appears,  while  hot,  of  a  dirty  green 
color,  blue  on  cooling ;  with  strong 
blowing  it  becomes,  on  cooling,  blu- 
ish-green. On  Ch  with  tin,  deep 
green.  If  iron  is  present  the  glass, 
on  cooling,  becomes  brownish-red; 
with  tin  on  Ch  the  glass  becomes 
blue  or,  if  the  amount  of  iron  is  con- 
siderable, green. 


OF1 :  Behaves  like  sesquioxide  of 
iron.  When  highly  saturated  the 
glass  may  be  made  enamel-yellow 
by  flaming. 

RF1 :  Behaves  like  sesquioxide  of 
iron.  The  green  bead,  when  at  a 
certain  point  of  saturation,  may  be 
made  black  by  flaming.  On  Ch 
with  tin  it  becomes  dark-yellow. 


OF1  -.  Dissolves  to  a  limpid  yellow 
glass  which,  on  cooling,  becomes 
yellowish-green. 

RF1 :  The  glass  assumes  a  dirty 
green  color  which,  on  cooling, 
changes  to  a  fine  green.  With  tin 
on  Ch  the  color  deepens. 


OF1 :  Dissolved  to  a  limpid  glass 
which,  when  the  quantity  of  vanadic 
acid  is  small,  appears  colorless, 
when  larger  yellow,  and  which,  on 
cooling,  becomes  greenish. 

RF1 :  The  glass,  while  hot,  appears 
brownish,  and  assumes  a  fine  green 
color  on  cooling. 


OF1:  Soluble  to  a  limpid  glass 
which,  if  sufficient  vanadic  acid  is 
present,  appears  dark-yellow  while 
hot,  and  becomes  light-yellow  on 
cooling. 

RF1 :  As  with  Borax. 


160 


TABLE  II.— CON- 


Metallic  Oxides  in 
Alphabetical    Order. 


On  Charcoal  alone. 


With  Carbonate  of  Soda. 


27.  OXIDE  OF 
ZINC. 

ZnO. 


OFl:  When  heated  be- 
comes yellow  and,  on 
cooling,  white  again.  It 
fuses  not,  but  becomes 
very  luminous. 

IIF1 :  Is  slowly  reduced ; 
the  reduced  metal  be- 
comes rapidly  re-oxidized 
and  the  oxide  deposited 
on  another  place  of  the 
Ch. 


OFl;  Insoluble. 

EF1:  On  Chit  becomes 
reduced.  The  metal  vap- 
orizes and  coats  the  Ch 
with  oxide.  With  a  pow- 
erful flame  the  charac- 
teristic zinc-flame  is 
sometimes  produced. 


161 


TINUED. 


With  Bx  on  Platinum  Wire. 


With  SPh  on  Platinum  Wire. 


OF1 :  Dissolves  readily,  and  in 
large  quantity,  to  a  limpid  glass 
•which  appears  yellowish  while  hot ; 
on  cooling  it  is  colorless.  When 
much  of  the  oxide  is  present  the 
glass  may  be  made  enamel-white 
by  flaming ;  and  on  a  still  larger 
addition  it  becomes  enamel-white 
on  cooling. 

RF1:  The  saturated  glass  be- 
comes at  first  gray  and  cloudy,  and 
finally  transparent  again.  On  Ch 
the  oxide  becomes  reduced,  the 
metal  vaporizes  and  coats  the  Ch 
with  oxide. 


As  with  Borax. 


14* 


162 


TABLE  III.— THE   METALLIC  OXIDES  ARRANGED 

THEY  IMPART 

WITH  BORAX  IN  OXYDATION  FLAME  PRODUCE  : 
a. —  Colorless  Beads. 


HOT 


f      Silica,  Alumina,    Binoxide  of   Tin, 
Baryta,    Strontia,    Lime,     Magnesia, 
Glucina,     Yttria,     Zirconia,     Thoria,  |  -when  highly  saturated 
Oxide  of  Lanthanium,  Oxide  of   Sil-  ^-opaque      (white)       by 


AND   «j  ver,  Tantalic  Acid,  Niobic  Acid,  Tel-  |  flaming. 
COLD,     lurous  Acid. 

Titanic  Acid,  Tungstie  Acid,  Molyb- 1 

I  die  Acid,  Oxides  of    Zinc,  Cadmium,  >•  when  feebly  saturated. 
l_  Lead,  Bismuth,  and  Antimony.  J 


5. —  Yellow  Beads. 

Titanic  Acid,  Tungstic  Acid,  Oxides  ) 
of  Zinc,  and  Cadmium.      %  J  4™^*  fl^ng? 

Oxides    of    Lead,     Bismuth,     and  )  when  highly  saturated; 
Antimony.  /  on  cooling  colorless. 

HOT.   i       Sesquioxides  of  Cerium,  Iron,   and  "I  when  feebly  saturated ; 
Uranium.  /  on  cooling  colorless. 

Sesquioxide  of  Chromium,  when  fully  saturated;  when  cold, 
yellowish-green. 

Vanadic  Acid ;  when  cold,  pale-green. 

c. — Red  to  Brown  Beads. 

(      Sesquioxide  of  Cerium ;    on  cooling  yellow,   enamel-like  by 

I  flaming. 
Sesquioxide  of  Iron  ;  on  cooling  yellow. 

TT         J       Sesquioxide  of  Uranium  ;  on  cooling  yellow,  enamel-yellow  by 
"^  flaming. 

Sesquioxide  of  Chromium  ;  on  cooling  yellowish-green. 
Sesquioxide  of  Iron,  containing  Manganese  ;  on  cooling  yel- 
lowish-red. 

(      Oxide  of  Nickel  (reddish-brown  to  brown) ;  violet  while  hot. 
COLD.  <       Sesquioxide  of  Manganese  (violet-red) ;  violet  while  hot. 
(       Oxide  of  Nickel,  containing  Cobalt ;  violet  while  hot. 

d. —  Violet  Beads  (amethyst-colored). 

(       Oxide  of  Nickel ;   on  cooling  reddish-brown  to  brown. 
HOT.    <       Sesquioxide  of  Manganese  ;  on  cooling  violet-red. 

(      Oxide  of  Nickel,  containing  Cobalt ;   on  cooling  brownish. 


163 


WITH    KEFERENCE    TO    THE    COLORS    WHICH 
TO  THE  FLUXES. 

WITH  BORAX  IN  REDUCTION  FLAME  PRODUCE  : 

a. —  Colorless  Beads. 

Silica,  Alumina,  Binoxide  of  Tin. 

Baryta,   Strontia,  Lime,  Magnesia,  "] 

Glucina,  Yttria,  Zirconia,  Thoria,  Ox-  1  -when  highly  saturated 
ides  of  Lanthanium  and  Cerium,  Tan-  j  cloudy  by  flaming. 


HOT 

AND 

COLD. 


talic  Acid.  J 

Sesquioxide  of  Manganese  ;  sometimes,  on  cooling,  pale  rose- 


colored. 


Niobic  Acid  ;  when  feebly  saturated. 

Oxides  of  Silver,  Zinc,  Cadmium,  "j  with  strong  blowing ; 
Lead,  Bismuth,  Antimony,  Nickel,  Tel-  L  with  feeble  blowing 
lurous  Acid.  J  gray. 

HOT    /      Oxide  of  Copper ;  when  highly  saturated  on  cooling  opaque 
1  and  red. 


1). —  Yellow  to  Brown  Beads. 

f      Titanic  Acid  (yellow  to  brown) :  when  highly  saturated  en- 
j   amel-blue  by  flaming. 
HOT.  •{       Tungstic  Acid  (yellow  to  dark-yellow)  ;  when  cold  brownish. 

Molybdic  Acid  (brown  to  opaque). 
I      Vanadic  Acid  (brownish) ;  green  when  cold. 


c. — Blue  Beads. 
HOT.   -{       Oxide  of  Cobalt ;  retains  its  color  on  cooling. 


d. —  Green  Beads. 

JJOT    f      Sesquioxide  of  Iron  (yellowish-green) ;  especially  when  cold. 
Sesquioxide  of  Uranium  (yellowish-green) ;  when  highly  satu- 
AIN1     j  rated  black  by  flaming. 

|OLI)-  [      Sesquioxide  of  Chromium  (light  to  dark  emerald-green). 
HOT.    J      Vanadic  Acid;  brownish  while  hot. 


164 

TABLE  III.— CON- 


WITH  BORAX  IN  OXYDATION  FLAME  PRODUCE  : 

e. — Blue  Beads. 

HOT.  ^       Oxide  of  Cobalt ;  retains  its  color  on  cooling. 
n  j       Oxide  of  Copper  (when  highly  saturated  greenish-blue) ;  green 

L;OLD-  \  while  hot. 

f. —  Green  Beads. 

C      Oxide  of  Copper ;  when  cold  blue  or  greenish-blue. 

^  on  cooling  the  color 
changes,  according  to 
the  proportion  in 
>•  which  the  various  ox- 
ides are  present,  to 
light-green,  blue,  or 
yellow. 

Sesquioxide  of  Chromium,  yellowish-green ;    yellow  to   red 
while  hot. 

Vanadic  Acid,  greenish  ;  yellow  while  hot. 


Sesquioxide  of  Iron,  containing  Co- 
IIOT.    \  bait  or  Copper. 

Oxide  of  Copper,  containing  Iron  or 


165 
TINUED. 


WITH  BORAX  IN  REDUCTION  FLAME  PRODUCE  : 

e. —  Gray  and  Cloudy  Beads. 

f     Oxides   of   Silver,    Zinc,    Cadmium,  ^  with  feeble    blowing  ; 
p          J  Lead,  Bismuth,  Antimony,  Nickel,  Tel-  >  with    strong     blowing 
LD<  1  lurous  Acid.  )  colorless. 

{.     Niobic  Acid ;  when  highly  saturated. 


f. — Red  and  Opaque  Beads. 
COLD.  <{      Oxide  of  Copper,  when  highly  saturated ;  colorless  while  hot. 


166 

TABLE  III.— CON- 


WITH  SALT  OF  PHOSPHORUS  IN  OXYDATION  FLAME  PRODUCE  : 

a. —  Colorless  Beads. 

Silicic  Acid ;  soluble  only  in  minute  quantity. 
Alumina,  Binoxide  of  Tin ;  soluble  with  difficulty. 


HOT 

AND 

COLD. 


Baryta,  Strontia,  Lime,  Magnesia,  ^  when  highly  saturated 
Glucina,  Yttria,  Zirconia,  Thoria,  Ox-  [-become  opaque  by 
ide  of  Lanthanium,  Tellurous  Acid.  J  flaming. 

Acids  of  Tantalium,  Niobium,  TitanO  .»  , .  , ,    . 

lf  ™*  to°          l    8atu~ 


HOT. 


Acids  of  Tantalium,  Niobium,  Titan-  "|  . ,. 
ium,  Tungsten,  Antimony ;  Oxides  of  1 1    ,n^ 
Zinc,  Cadmium,  Lead,  Bismuth.  J  ra 

b. —  Yellow  Beads. 

Acids  of  Tantalium,  Niobium,  Titan-^j  M  M    saturated 

mm,  Tungsten,  Antimony;  Oxides  of  ^     ,     ,     6    ^       ,. 
Zinc,  Cadmium,  Lead,  Bismuth.  J  colorless  on  coolmS- 

Oxide  of  Silver,  yellowish ;   when  cold  opalescent. 

Sesquioxide  of  Iron.  )  when  feebly  saturated; 

"  "  Cerium.  $  on  cooling  colorless. 

"  "  Uranium;  when  cold  yellowish-green. 

Vanadic  Acid,  deep-yellow ;  when  cold  of  a  lighter  shade. 
CoLD.  •{       Oxide  of  Nickel ;  while  hot  reddish. 

c. — Red  Beads. 

f      Sesquioxide  of  Iron.  )  when  highly  saturated; 

„       j  "  "  Cerium.  $  when  cold  yellow. 

HOT.  s       Oxide  of  Nickel,  reddish ;  when  cold  yellow. 

[      Sesquioxide  of  Chromium,  reddish  ;  when  cold  emerald-green. 

d. —  Violet  Beads. 

{Sesquioxide  of  Manganese,  brownish- violet ;  on  cooling  pale 
reddish-violet. 
Oxide  of  Didymium  ;  when  cold  of  a  lighter  shade. 

e. — Blue  Beads. 

HOT.  -{  Oxide  of  Cobalt ;  when  cold  of  the  same  color. 
COLD.  1  Oxide  of  Copper ;  green  while  hot. 

f. —  Green  Beads. 

~\  on    cooling   the   color 

Sesquioxide  of  Iron,   containing  Co-  f  changes,  according  to 
bait  or  Copper.  !  the  proportion  inwhich 

Oxide  of  Copper,  containing  Iron  or  [  the  various  oxides  are 
HOT.  \  Nickel.  |  present,  to  light  green, 

J  blue,  or  yellow. 

Oxide  of  Copper ;  when  cold  blue  or  greenish-blue. 
(^      Molybdic  Acid,  yellowish-green ;  when  cold  of  a  lighter  shade. 
Co        f      Sesquioxide  of  Uranium,  yellowish-green;  while  hot  yellow. 
'  \      Sesquioxide  of  Chromium,  emerald-green ;  while  hot  reddish. 


167 
TINUED. 


WITH  SALT  or  PHOSPHORUS  IN  REDUCTION  FLAME  PRODUCE  : 

a. —  Colorless  Beads. 

Silica,  but  slightly  soluble. 

Alumina,  Binoxide  of  Tin,  soluble  with  difficulty. 

Baryta,  Strontia,  Lime,  Magnesia,    ~\  when  highly  saturated 


HOT 

AND 

COLD. 


HOT.  s 


Glucina,  Yttria,  Zirconia,  Thoria,  Ox-  [•  become      opaque      by 
ide  of  Lanthanium.  J  flaming. 

Oxides  of  Didymium,  Cerium,  Manganese. 

Oxides  of  Silver,   Zinc,   Cadmium,  ~j 
Lead,  Bismuth. 

Tantalic    Acid,    Antimonous    Acid,   >  with  continued  blowing. 
Tellurous  Acid. 

Oxide  of  Nickel,  on  Ch. 

1}.  —  Yellow  to  Red  Beads. 

Sesquioxide  of  Iron  ;  on  cooling  greenish,  then  reddish. 

Titanic  Acid,  yellow  ;  on  cooling  violet. 

Vanadic  Acid,  brownish  ;  when  cold  emerald-green. 

Titanic  Acid  containing  Iron.  ">  yellow;      when      cold 

Tungstic  "  "  "  /blood-red. 

Niobic       "  "  "  ^  brownish  red  ;       when 

j  cold  deep-yellow. 

c.  —  Violet  Beads. 

Niobic  Acid,  when  highly  saturated  ;  while  hot  of  a  pale  dirty- 

yellow  while  hot. 

d.  —  Blue  Beads. 

f     Oxide  of  Cobalt;  of  the  same  color  when  hot. 
p  !      Tungstic  Acid  ;  while  hot  brownish. 

bOLD.  -j      Niobic  Acid,  when  very  highly  saturated  ;  while  hot  of  a  dirty  - 

[  blue  color. 

e.  —  Green  Beads. 

f  Sesquioxide  of  Uranium  ;  while  hot  less  bright. 

p  !  Molybdic  Acid  ;  while  hot  of  a  dirty-green  color. 

l^OLD.  -j  Vanadic  Acid  ;  while  hot  brownish. 

[_  Sesquioxide  of  Chromium  ;  while  hot  reddish. 

f.  —  Gray  and  Cloudy  Beads. 

(      Oxides   of  Silver,    Zinc,   Cadmium,  ~|  takes  quickest  place  on 
COLD.  •]  Lead,    Bismuth,    Antimony,     Nickel  ;  [-Ch  ;     with     continued 
[  Tellurous  Acid.  J  blowing  colorless. 

g.  —  Red  and  Opaque  Beads. 

COLD.  *!      Oxide  of  Copper,  when  highly  saturated,  or  with  Tin  on  Ch. 


{Niobic  Acid,  w 
blue  color. 
Titanic  Acid  ; 


INDEX. 


ACICUL All  BISMUTH,  113 
Acid?,  volatile,  tests  for,  IS 
Acmite,  121 
Aeschynite,  140 
Agalmatolite,  132 
Aikinite,  113 
Albite,  129 
Allanite,  114,  121 
Allophane,  131 
Allochroite,  121 
Almandine,  122 
Altaite,  111 

Alumina,  tests  for,  30,  144 
Alunite,  130 
Amalgam,  81,  114 
Amalgams,  test  for,  20,  22 
Amblygonite,  124 
Ammonia,  test  for,  19,  33 

"          salts  of,  test  for,  19 
Ammonia-alum,  124 
Analcime,  126 
Anatase,  139 
Andalusite,  132 
Anglarite,  120 
Anglesite,  76,  117 
Anhydrite,  123 
Annabergite,  83,  119 
Anthophyllite,  139 
Anthracite,  90 
Antigorite,  137 
An timonial  copper,  112 

"  silver,  84 

Antimonous  acid,  tests  for,  19,  148 


Antimony,   metallic,  tests  for,   21, 

22,  27 

"  test  for,  when  in  combi- 

nation, 33 
"  ores  of,  56 

"  sulphides  of,  test  for,  20 

"  "  "  when 

in  combination,  34 
Apatite,  124,  135 
Apophyllite,  126 
Apparatus,  list  of,  14,  16 
Ai'aeoxene,  117 
Arfvedsonite,  121 
Argentiferous  sulphide   of  copper, 

87 

Arkansite,  115 
Arragonite,  133 
Arsenates,  test  for,  27 
Arsenic,  metallic,  testi  for,   19,  20, 

22,  26 

"         ores  of,  58 
"         sulphides  of,  test  for,  20 
"         test  for,  when  in  combina- 
tion, 34 
"         test  for,  in  arsenates  and 

arsenites,  35 
Arsenical  pyrites,  71,  110 

"         copper,  65 
Arseniosiderite,  119 
Arsenolite,  58,  116 
Arsenous  acid,  tests  for,  19,  35,  148 
Asphaltum,  91 
Atacamite,  65,  118 


15 


170 


Augite,  129 
Axinite,  129 
Azurite,  66,  119 

BARIUM,  salts  of,  test  for,  26 

Baryta,  tests  for,  144 

Barytes,  123 

Barytocalcite,  134 

Berthierite,  57,  112 

Beryl,  141 

Berzelianite,  111 

Beudantite,  119 

Biotite,  138 

Bituminous  coal,  90 

Bismuth,  metallic,  tests  for,  21,  23 
"         oxide  of,  change  by  heat, 

21 

"  "     tests  for,  148 

"        test  for,  when  in  combina- 
tion, 36 

Bismuth  ochre,  60 

Bismuthine,  60 

Bismutite,  59,  122 

Black  manganese,  79 

Blende,  88,  115,  133,  134 

Blowpipe  lamp,  13 

Blue  malachite,  66 

Bog  manganese.  79 

Boltonite,  138 

Bone-ash,  16 

Boracic  acid,  as  reagent,  15 
tests  for,  26,  36 

Boracite,  124 

Borax,  123 

"      as  reagent,  15 

Botryogen,  120 

Boulangerite,  75,  112 

Bournonite,  74,  111 

Braunite,  79,  115 

Breithauptite,  112 

Breunnerite,  134 

Brewsterite,  127 

Brittle  silver  ore,  86 

Brochantite,  118 

Bromine,  test  for,  37 

Bromic  silver,  85 

Bromyrite,  85 


Bronzite,  139 
Brookite,  139 
Brown  coal,  90 
Brown  hematite, 
Brucite,  133 


70 


CACOXENE,  120 

Cadmium,  metallic,  test  for,  23 

test  for  small  quantities 

of,  37 

"          alloys  of,  test  for,  20 
"         oxide  of,  tests  for,  148 

Calamine,  89,  130,  133 

Calcination  of  assays,  27 

Calcite,  133 

Calcium,  salts  of,  test  for,  26 

Calomel,  81,  116 

Capillary  pyrites,  83 

Carbonic  acid,  test  for,  19 

Carpholite,  128 

Cassiterite,  87,  139 

Celestine,  123 

Cerasine,  75,  117 

Cerite,  136 

Cerium,  oxide  of,  tests  for,  150 

Cerusite,  75,  117 

Chabazite,  127 

Chalcolite,  119 

Chalcophyllite,  118 

Chalcopyrite,  63 

Chalybite,  72,  134 

Childrenite,  135,  140 

Chiolite,  124 

Chloantite,  110 

Chlorine,  test  for,  37 

Chlorite,  137,  138 

Chloropal,  136 

Chloro-bromide  of  silver,  84 

Chondrodite,  138 

Chonikrite,  126 

Chrome  ochre,  135 

Chromic  iron,  60,  115 

Chromium,  ores  of,  60 

"  oxide  of,   tests  for,  38, 

150 

Chrysoberyl,  132 

Chrysocolla,  68,  136 


171 


Chrysolite,  138 
Chrysotile,  136 
Cimolite,  131 
Cinnabar,  81,  113,  116 

"         test  for,  20 
Clausthalite,  110 
Clintonite,  131,  137 
Cobalt,  test  for,  in  arsenides,  38 
"        in  sulphides,  39 
"        when   in   combina- 
tion with  metals, 
43 

"       nitrate  of,  as  reagent,  15 

"       oxide  of,  tests  for,  150 

"        ores  of,  61 
Cobalt  bloom,  62 
Cobalt  pyrites,  61 
Cobaltine,  61,  110 
Collyrite,  131 
Columbite,  115 
Common  coal,  90 
Common  salt,  123 
Copiapite,  120 
Copper,  test  for,  in  sulphides,  40 

"  "       when  in  combina- 

tion with  other 
metals,  39,  40 

"  "       when  in  combina- 

tion with  tin,  52 

"        ores  of,  63 

"        oxide  of,  tests  for,  150 

"  "     as  reagent,  16 

"        salts  of,  tests  for,  26,  27, 

41 
Copper  glance,  64,  113 

"      nickel,  81,  110 

"      pyrites,  63,  113 

"       vitriol,  66 
Copperas,  72 
Coqmmbite3  120 
Corneous  lead,  75 
Corundum,  132 
Covelline,  118 
Grocidolite,  121 
Crocoisite,  77,  117 
Cronstedtite,  121 
Cryolite,  123 


Cuban,  113 

Cupellation,  process  of,  50 
Cuproplumbite,  113 
Cyanogen,  test  for,  19 
Cyanosite,  66,  118 

DATHOLITE,  124 
Dark  red  silver  ore,  85 
Deweylite,  127 
Diallage,  128 
Diallogite,  80,  134 
Diamond,  141 
Diaspore,  131 
Dioptase,  136 
Diopside,  129 
Discrasite,  84,  112 
Disterrite,  132 
Dolomite,  134 
Domeykite,  65,  110 
Dufrenite,  120 
Dufrenoysite,  75,  110 

EARTHY  COBALT,  62,  135 

Ehlite,  119 

Electrum,  110 

Embolite,  84 

Emerald  nickel,  83,  134 

Epidote,  128,  129 

Epsomite,  122 

Erinite,  118 

Erubescite,  63 

Erythrine,  62,  119 

Eucairite,  111 

Euchroite,  118 

Euclase,  141 

Eudialite,  125 

Eukolite,  126 

Eulytine,  122 

Euphyllite,  128 

Examination  in  a  closed  glass  tube, 

18 
in  an  open  glass  tube, 

21 

"  on  charcoal,  22 

"  in  the  forceps,  24 

"  with  borax  and  salt  of 

phosphorus,  27 


172 


Examination  with  carbonate  of  soda, 

28 

"  with  solution  of  cobalt, 

30 

FISCHERITE,  131 
Flaming,  process  of,  28 
Fluocerite,  136 
Fluor,  123 

Fluor  spar,  as  reagent,  15 
Fluorine,  tests  for,  41 
Fossil  fuel,  90 
Franklinite,  80,  115 
Fusibility,  scale  of,  107 

GADOLINITE,  137 
Gahnite,  141 
Galena,  74,  113 
Gay-Lussite,  123 
Gehlenite,  137 
Geocronite,  75,  112 
Gersdorffite,  82,  110 
Gibbsite,  130 
Glaserite,  122 
Glauberite,  123 
Glauber  salt,  122 
Glucina,  tests  for,  146 
Gold,  test  for,  when   in  combina- 
tion, 42 

"       ores  of,  68 

"      oxide  of,  tests  for,  152 
Goslarite,  124,  133 
Goethite,  134 
Graphic  tellurium,  69 
Graphite,  115 
Gray  antimony,  56 

"     copper,  64 

"     ore  of  manganese,  79 
Green  earth,  121 

"      vitriol,  72,  120 
Greenockite,  134 
Grunauite,  113 
Gypsum,  123 

HALLOYSITE,  131 
Hardness,  scale  of,  56 
Harmotome,  129 


Hauerite,  113,  124 
Hausmannite,  79,  115 
Hauyne,  125 
Hedenbergite,  121 
Hedyphane,  117 
Kelvin,  125 

Hematite,  70,  114,  115,  120,  134 
Heteromorphite,  75 
Hessite,  111 
Hisingerite,  121,  136 
Horn  quicksilver,  81 
Horn  silver,  84,  116 
Hornblende,  121,  129 
Hureaulite,  120 
Hydroboracite,  124 
Hydromagnesite,  133 
Hypersthene,  139 

IDOCRASE,  130 
Ilmenite,  72 
lodic  silver,  85 
Iodine,  test  for,  43 
lodirite,  85,  116 
lolite,  140 
Iridium,  ores  of,  68 

' '        oxide  of,  tests  for,  152 
Iridosmine,  69,  115 
Iron,  metallic,  as  reagent,  16 

test  for,  when  in  combination, 

43,  44 

"      in  sulphides  and  arse- 
nides, 44 
"     oxide  of,  tests  for,  152 

"      change  by  heat,  21 
"      ores  of,  69 
Iron  garnet,  122 
Iron  pyrites,  70,  113 

JAMESONITE,  75,  111 

KAOLIN,  131 

Kerargyrite,  84 
Kermesite,  57 
Kilbrikenite,  112 
Kreittonite,  141 
Kyanite,  132 

LABRADORITE,  127 


173 


Lanarkite,  117 

Lapis  lazuli,  125 

Laumontite,  125 

Lavendulan,  62 

Lazulite,  131 

Lead,  metallic,  as  reagent,  16 

"        tests  for,  23,  27 
' '      test  for,  when  in  combination, 

44,  45 
"      oxide  of,  change  by  heat,  21 

"      tests  for,  152 
"      ores  of,  73 

"      phosphate  of,  test  for,  48 
Leadhillite,  76,  117 
Lead  vitriol,  76 
Lepidolite,  122,  128 
Leucite,  133,  138 
Libethenite,  119 
Lievrite,  114,  121 
Light-red  silver  ore.  86 
Liine,  tests  for,  144 
Lime-garnet,   127,  130 
Lime-chrome-garnet,  141 
Lime-iron-garnet,  121 
Limonite,  70,  113,  115,  134 
Linnajite,  61 
Linarite,  117 
Liroconite,  118 
Lithia,  test  for,  25 

"      in  silicates,  45 
Lithia-tourmaline,  132 

MAGNESIA,  tests  for,  30,  144 
Magnesite,  134 
Magnetic  iron  ore,  70 
"        pyrites,  71 
Magnetite,  70,  114,  115 
Malachite,  66,  119 
Manganblende,  113,  124 
Manganese,  test  for,  when  in  com- 
bination, 46 

ores  of,  79 

oxide  of,  tests  for,  154 
Manganese-garnet,  128 
Manganite,  115 
Marcasite,  71,  113 


Margarite,  128 

Marmatite,  134 

Mascagnine,  116 

Matlockite,  117 

Meerschaum,  127,  136 

Meionite,  126 

Melaconite,  118 

Melanochroite,  117 

Melinite,  126 

Mendipite,  117 

Mercury,  metallic,  tests  for,  20,  22 
;'        chlorides  of,  test  for,  19 
"         salts  of,  tests  for,  20,  46 
"        sulphide  of,  tests  for,  20, 

46 

"         ores  of,  80 
"        oxide  of,  tests  for,  154 
test  for,  in  amalgams,  46 

Mesolite,  125 

Meteoric  iron,  69 

Miargyrite,  112 

Millerite,  83,   118 

Mimetine,  117 

Minium,  73,  117 

Mispickel,  71 

Molybdenite,  115 

Molybdenum,    compounds    of,    test 
for,  26 

Molybdic  acid,  tests  for,  154 

Molybdine,  122 

Monazite,  135 

Monradite,  137 
Muscovite,  132,  138 
Myelin,  132 
Mysorin,  119 

NAGYAGITE,  111 
Native  antimony,  111 

"       arsenic,  58,  110 

"       bismuth,  59,  114 

"      copper,  63,  110 

"      gold,  68,  110 

"       iron,  110 

"      lead,  110 

"      mercury,  80,  110 

"       palladium,  110 
platinum,  69,  110 


174 


Native  silver,  83,  109 

"      sulphur,  116 

"       tellurium,  111 
Natrolite,  125 
Natron,  122 
Naumannite,  111 
Neolite,  137 
Nepheline,  126 
Nickel,  nitrate  of,  as  reagent,  15 

"      test  for,  when  in  combina- 
tion, 46 

"      ores  of,  81 

"       oxide  of,  tests  for,  154 
Nickel  glance,  82 
Nickel  green,  83 
Nickeliferous  gray  antimony,  82 
Nitratine,  122 
Nitre,  122 

Nitric  acid,  test  for,  47 
Nitrous  acid,  "  19 
Nosean,  125 

OBSIDIAN,  130 

Ochran,  131 

Okenite,  126 

Olivenite,  67,  118 

Onofrite,  110 

Opal,  140 

Orpiment,  58,  116 

Orthoclase,  129,  140 

Osmium,  oxide  of,  tests  for,  156 

Osmium-iridium,  69 

Ouvarovite,  141 

Oxygen,  test  for,  18 

PALLADIUM,  oxide  of,  tests  for, 

156 

Pearlstone,  130 
Pectolite,  126 
Peganite,  131 
Perofskite,  115 
Petalite,  128 
Pharmacolite,  123 
Phenacite,  141 
Philippsite,  125 
Pholerite,  131 
Phosphate  of  lead,  76 


Phosphocalcite,  67,  119 
Phosphoric  acid,  tests  for,  26,  47 
Phosphorus,  salt  of,  as  reagent,  15 
Pitchblende,  116,  134 
Pitchstone,  130 
Pitticite,  119 
Plagionite,  75,  112 
Platinum,  ores  of,  68 

"         oxide  of,  tests  for,  156 
Plattnerite,  114 
Pleonaste,  141 
Plumbic  ochre,  73 
Plumbo  resinite,  77,  130 
Plumosite,  112 
Polybasite,  86,  110 
Polycrase,  135 
Polyhallite,  123 
Polytelite,  112 
Potash  alum,  122 
Potassa,  tests  for,  25,  48 

"        bisulphate  of,  as  reagent, 
15 

"        oxalate  of,  " 

29 
Potassium,  cyanide  of,        " 

29 

Prehnite,  127 
Proustite,  86,  116 
Psilomelane,  79,  114,  115 
Pumice,  130 
Purple  copper,  63,  113 
Pyrargyrite,  85 
Pyrochlore,  140 
Pyrolusite,  79,  115 
Pyromeline,  119 
Pyrope,  130 
Pyrophyllite,  132 
Pyrosclerite,  126 
Pyrosmalite,  121 
Pyrrhotine,  71 

QUARTZ,  140 

REAGENTS,  list  of,  14,  16 
llealgar,  58.  116 
Red  antimony,  57,  116 
Red  copper,  66,  114,  118 


175 


Red  lead  ore,  77 
lied  zinc  ore,  88 
Rhodonite,  114,  122,  128 
Ripidolite,  137,  138 
Ruby  silver,  85,  116 
Rutil,  115,  139 

SAL  AMMONIA,  116 

Salt  of  phosphorus,  as  reagent,  15 

Samarskite,  114 

Sassolin.  124 

Scale  of  fusibility,  107 

"      hardness,  56 
Scapolite,  127 
Scheeletine,  117 
Scheelite,  128,  139 
Schillerspar,  136 
Scolecite,  125 
Scorodite,  73,  119 
Selbite,  116 

Selenide  of  mercury,  110 
Selenides,  tests  for,  20,  22 
Selenium,  tests  for,  20,  22,  23,  27, 

48 

Selenquecksilberblei,  110 
Serpentine,  137 
Silicates,   behavior  of,  with  salt  of 

phosphorus,  49 
Silicic  acid,  tests  for,  28,  49 
Silver,  metallic,  test  for,  23 

"      test  for,  when  in  combina- 
tion, 49,  50 

"       chloride  of,  as  reagent,  16 

"       ores  of,  83 

"       oxide  of,  tests  for,  156 
Silver  glance,  85,  113 
Skopolite,  125 
Smaltine,  61,   110 
Smithsonite,  89,  133 
Soda,  test  for,  25 

"      carbonate  of,  as  reagent,  15 
Sodalite,  125 
Spathic  iron,  72,  120 
Specular  iron,  70 
Sphene,  127,  129 
Spinel,  113,  141 
Spodumene,  128 


Staurotide,  140 
Steinmannite,  112 
Stephanite,  86,  112 
Sternbergite,  113 
Stibnite,  56,  111 
Stilbite,  127 
Stromeyerite,  87,  113 
Strontia,  tests  for,  144 

"        salts  of,  test  for,  26 
Strontianite,  134 
Sulphides,  tests  for,  20,  51 

"          distinction  of,  from  sul- 
phates, 51 

Sulphur,  tests  for,  20,  21,  51 
Sulphuretted  hydrogen,  test  for,  19 
Sulphurous  acid,  test  for,  18 
Supports,  14 
Sylvanite,  69,  111 

TACHYLYTE,  127 
Tagilite,  119 
Talc,  138 
Tantalite,  115 
Tellurides,  test  for,  22 
Telluric  bismuth,  59 
Tellurium,  tests  for,  20,  22,  24 

"  "  when  in  combi- 

nation, 52 
"  ores  of,  111 

Tellurous  acid,  tests  for,  19,  26,  156 
Tennantite,  65,  110 
Tenorite,  118 
Tephroite,  125 
Test-paper,  16 
Tetradymite,  59,  111 
Tetrahedrite,  64,  112 
Thenardite,  122 
Thomsonite,  125 
Thorite.  136 
Tin,  metallic,  as  reagent,  16 

"          "          tests  for,  23,  52 

"     ores  of,  87 

"     oxide  of,  change  by  heat,  21 

tests  for,  30,  150 
Tin  ore,  87 
Tin  pyrites,  87,  113 
Titanic  acid,  tests  for,  28,  158 


176 


Titanic  acid,  tests  for,  when  in  com- 
bination, 53 

Titaniferous  iron,  72,  115 
Topaz,  132 
Tourmaline,  121,  129 
Tremolite,  129 
Triphiline,  120 
Triplite,  120 
Trona,  122 

Tungstic  acid,  tests  for,  28,  158 
Turquois,  135 
Tyrolite,  69,  118 

TJLLMANNITE,  82,  112 

Uranite,  124 

Uranium,  test   for,  in   presence   of 

iron,  53 
"        oxide  of,  tests  for,  158 

VALENTINITE,  116 
Vanadic  acid,  tests  for,  158 
Vanadinite,  118 
Vauquelinite,  78,  118 
Vivianite,  73,  120 

WAD,  79,  135 

Wagnerite,  124 

Water  of  crystallization  and  hydra- 

tion,  tests  for,  18 
Wavellite,  130 
Websterite.  130 
White  arsenic,  58 

<;      iron  pyrites,  71 


White  lead  ore,  75 
Whitherite,  123 
Willemite,  131,  133 
Wittichite,  113 
Wrchlerite,  127 
Wolfram,  114 
Wolframite,  139 
Wolfsbergite,   112 
Wollastonite,  125 
Wulfenite,  78,  117 

XANTHOCONE,  116 
Xenotime,  140 
Xylotile,  121,  136 

YELLOW  LEAD  ORE,  78 
Yttria,  tests  for,  146 
Yttro-cerite,  134 
Yttro-tantalite,  115 

ZINC,  metallic,  test  for,  23 

"       test  for,  when  in   combina- 
tion, 54 
"       ores  of,  88 

"       oxide  of,  change  by  heat,  20 
"  "      tests  for,  30,  160 

Zinc  bloom,  133 

Zincite,  88,  135 

Zinkenite,  75,  111 

Zippeite,  135 

Zircon,,.  141 

Zirconia,  'tests  for,  1-1 G 

Zoisite,  129 


YB 


^  J  r\  i    4 
1*4 


